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I. ' 



WOODEN BOX 

AND 

CRATE CONSTRUCTION 



■1^^%,U-^^ ^^^^ PREPARED BY 

FOREST PRODUCTS LABORATORY 

V. 8. DEPARTMENT OF AORIODLTURE 

FOREST SERVICE 

MADISON, WISCONSIN 



PUBLISHED BY 

NATIONAL ASSOCIATION OF BOX MANUFACTURERS 

1553 CONWAY BUILDING 

CHICAGO, ILLINOIS 

1921 






-T5v.'i'\c.— 4^ 



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PUBLISHER'S INTRODUCTION 

The National Association of Box Manufacturers is an 
organization of the leading manufacturers of wooden boxes 
of every section of the country. Many of its members also 
make other types or kinds of boxes, but the association con- 
fines its activities to the interests of the wooden box. 

The association aims to promote all projects of genuine 
interest to its members ; to obtain a unity of action in mat- 
ters affecting the wooden box industry ; to advertise properly 
the merits of wooden boxes, and to be, in fact, a constructive 
influence in the improvement of conditions in the industry 
and better service for consumers. And by the same token 
the association stands guard against any project or practice 
which may, in any way, bring wooden box service into dis- 
favor or disrepute. 

The association believes in the scientific construction of 
packing boxes. It believes that the dissemination of knowl- 
edge among box users, as well as manufacturers, as to what 
has already been accomplished and what is now being done 
along the lines of scientific research in box construction, is 
to the mutual advantage of all. Such knowledge enlarges the 
field of usefulness of the wooden box, and leads to conserva- 
tion of material and lowering of costs, all of which tends to 
stabilize the use of wooden boxes, and the business of the 
manufacturer. This is the reason for publishing this book. 

The book includes, in a general way, all the latest and 
mast accurate information available on box and crate design. 
However, details applicable to different kinds of boxes for 
carrying special commodities vary with each commodity, 
hence the application of the fundamental principles discussed 
in this book must be made by each manufacturer and indi- 
vidual user of such boxes, except, of course, as the principles 
apply to boxes which have already been standardized as to 
specifications. 

Standardization of boxes and crates is a recognized aim 
of the association. Many packages have already been stand- 
ardized and many others are being studied with a view to 
standardization. 



Much valuable information on boxes for carrying certain 
commodities has been obtained as a result of these studies. 
No attempt has been made to include that information in this 
book, but it is available and will be freely given to those who 
have need for it. 

All of the machinery of the association is at iSie service 
of the public in any matters pertaining to the development of 
better packing methods or in solving any packing problem. 

The National Association 
OF Box Manufacturers. 

1553 Conway Building. 
Chicago, Illinois, 
March 1, 1921. 



INTRODUCTION 

The Forest Products Laboratory is a research unit of the 
Forest Service, U. S. Department of Agriculture. It is located 
at Madison, Wisconsin, where it was established in 1910 in 
co-operation with the University of Wisconsin. Its purpose 
is to acquire, disseminate and apply useful knowledge of the 
properties, uses and methods of utilization of all forest prod- 
ucts and thereby to promote economy and efficiency in the 
processes by which forests are converted into commercial 
products. In this work 220 research technologists are em- 
ployed. Its field of investigations and activities embraces : 

1. Obtaining authoritative information on the mechanical 
and physical properties of commercial woods and products 
derived from them ; 

2. Studying and developing the fundamental principles 
underlying the seasoning and kiln-drying of wood, its pre- 
servative treatment, its use for the production of fiber prod- 
ucts (pulp, paper, fiber board, etc.). and its use in the manu- 
facture of alcohol, turpentine, rosin, tar and other chemically 
derived products ; 

3. Developing practical ways and means of using wood 
which, under present conditions, is being wasted ; 

4. Co-operating with consumers of forest products in im- 
proving present methods of use ; also in formulating specifi- 
cations and grading rules for commercial woods and materials 
obtained from them, and for material used in the preservative 
treatment of wood ; and 

5. Making the information obtained available to the pub- 
lic through publications, correspondence, and by other means. 

Commercial research and mechanical tests on containers 
were begun in 1915 in co-operation with the National Associa- 
tion of Box Manufacturers, the National Canners' Associa- 
tion, and the National Wholesale Grocers' Association. 
Methods of testing and testing equipment were developed 
which have since become more or less standard for the box 
industry. From the data accumulated by the laboratory, the 
War Department prepared during the war general specifica- 



tions for overseas containers. At the laboratory in Madison, 
many containers to be used for the shipment of war equipment 
were tested and redesigned along more economical lines, in- 
cluding increase in strength, decrease in amount of material 
required, decrease in cubic contents and a consequent reduc- 
tion of ocean freight costs. 

Since the war the laboratory has co-operated with many 
associations and companies in testing and studying the con- 
struction of many different types of containers such as those 
used for the shipment of electric lamps, cream separators, 
small tractors, talking machines, boiler castings, furniture, 
paints and oils, piano benches, fruit baskets and crates, and 
shoes. 



CONTENTS 

Page 

Publisher's iNXRonucxiON v 

I NTRODUCTION vii 

List of Tables xiv 

List of Plates xiv 

List of Figures xv 

CHAPTER I 

Use of Wood in Box and Crate Construction 

Adaptability 1 

Availability 1 

Cost : 1 

Salvage value 1 

Qualities 2 

Desirable qualities 2 

Kinds and Amounts of Lumber Used 2 

The choice of species . . ." 2 

Amount of each kind of lumber used 3 

Consumption of box lumber by States 3 

Distribution of box lumber 5 

Commercial Grades and Sizes of Lumber Available for Box 

Construction 8 

Standard Defects and Blemishes in Lumber 8 

Grading According to Size of Lumber •. . . 10 

Standard sizes of lumber 10 

Grades suitable for boxes and crates 11 

Important Physical Properties of Wood Which Influence Its Use 

IN Box Construction 14 

Weight 14 

Importance 14 

How the weight of lumber is expressed 14 

Factors Which Influence the Weight of Lumber 14 

Species 14 

Density, or amount of wood substance 15 

Moisture content 15 

Resin content 15 

Moisture Content '. 15 

Importance 15 

How determined 15 

Variation 16 

How the moisture is contained in wood 16 

Proper moisture content of box lumber 17 

Shrinking and Swelling of Wood . 22 

Fxtent 22 

How Troubles from Shrinking and Swelling May Be Reduced to 

a Minimum in Boxes 23 

Checking 25 

ix 



X CONTENTS 

Page 

Cupping 25 

Casehardening : jrl 

Honeycombing ■ 25 

Color 25 

Odor and taste ^^ 

AIechanical or Strength Properties of Wood 26 

Meaning of strength 26 

Tensile strength 26 

Compression strength 26 

Shearing strength 26 

Strength as a beam 28 

Stiffness 30 

Shock-resisting ability 30 

Hardness i 30 

Nail-holding power - 30 

Care and Seasoning of Lumber in Storage 30 

Possible Deterioration in Stored Lumber 31 

Checking at ends and on surfaces 31 

Twisting and cupping 31 

Casehardening, honeycombing, and collapse 31 

Blue stain or sap stain 31 

Decay or rot 31 

Insect attack 32 

Proper methods of piling lumber in the yard 32 

Foundations and skids 35 

Stickers 35 

Placing of lumber 36 

Size and spacing of piles 36 

Kiln-drying box lumber 36 

The Use of Veneer in the Construction of Packing Boxes 2>7 

Definition ^7 

Manufacture of Veneer 37 

Method of cutting 2>7 

Drying 38 

Woods Used for Box Veneers 38 

Use of plywood in packing boxes 39 

CHAPTER H 

Box Design 

Factors Influencing Details of Design 41 

Lumber and Veneer 41 

Availability and supply 41 

Cost 42 

Manufacturing Limitations 42 

Equipment 42 

Cost of operation 42 

Styles of boxes 42 

Balanced Construction and Factors Affecting Strength 43 

Width of stock and joints 43 

Corrugated fasteners 45 

Physical properties of wood 45 

Moisture content 47 

Defects 48 

Nailing qualities of wood 51 

Fastenings and reinforcements 53 

Directions for nailing , 55 



CONTENTS xi 

Pace 

Side nailing 56 

Nails for clinching 56 

Large nail heads 57 

Overdriving nails 58 

Screws 59 

Staples :•••-.•••. ^^ 

Strapping and wire bindings 60 

Types of metal bindings 60 

Reinforcements and Handles 62 

Corner irons, hinges, and locks 62 

Battens 62 

Hand-holds and handles 62 

Characteristics of the Various Styles of Boxes 64 

Nailed boxes 64 

Lock-corner boxes 66 

Dovetail boxes 67 

Wirebound boxes 67 

Panel boxes 70 

Factors Determining the Amount of Strength Required 70 

Contents 70 

Hazards of transportation 71 

Factors Determining the Size of a Box 73 

Gross weight 73 

Desired quantity / 73 

Nesting, disassembling, or knocking down contents 73 

Minimum displacement 73 

Traffic limitations 74 

Special Constructions 74 

Protection of fragile and delicate contents 74 

Vermin 76 

Thieving 76 

CHAPTER HI 

Crate Design 

Factors Affecting Strength of Crates 77 

Influence of Styles of Crates on Strength 77 

Types of corner construction 77 

Frame members 78 

Skids 79 

Bracing long crates 79 

Fitting and fastening braces 80 

Scabbing 80 

Sheating 81 

Physical Properties of Wood Affecting Strength 81 

Relative thickness of material 81 

Moisture content 81 

Defects 81 

Nailing and bolting qualities of wood 81 

Fastenings and Reinforcements 82 

Nails and nailing 82 

Bolts and bolting 83 

Lag screws 84 

Straps 84 

Binding rods 84 

Internal bracing '. 84 



xH CONTENTS 

Page 

Factors Determining Amount of Strength Required in Crates.. 85 

Hazards of Transportation 85 

Factors Influencing the Size of Crates oo 

CHAPTER IV 

Box and Crate Testing 

Methods of Testing and Their Significance 87 

Drum Test "^ 

Drop Tests 



92 



Drop-cornerwise test 



92 



Drop-edgewise test 92 

Compression Tests ^2 

Compression-on-an-edge test 92 

Compression-cornerwise test 96 

Compression-on-faces test 96 

Supplementary Tests 96 

CHAPTER V 

Box and Crate Specifications 

Purpose 97 

Standardization of Packing Boxes 98 

General Specifications for Wooden Boxes, Nailed and Lock- 
corner Construction 99 

Material 99 

Grouping of Woods 100 

Thickness of Lumber ; 100 

Thickness of parts 100 

Width of parts 101 

Surfacing 101 

Joining 101 

Schedule of Nailing 101 

Size of nails 101 

Spacing of nails 102 

Specific Specifications for Nailed and Lock-Corner Boxes 103 

Canned Food Cases 103 

General Specifications for 4-One and Similar Boxes 103 

General form 104 

Grouping of woods 104 

Materials 105 

Cleats 105 

Thin boards 105 

Staples 105 

Assembling 105 

Boxes with wedgelock ends 106 

Boxes with detached tops 107 

CHAPTER VI 
Structure and Identification of Woods 

Structure of Wood 109 

Heartwood and Sapwood 109 

Annual Rings 110 

Springwood and Summerwood 110 

The Structure of Hardwoods 112 



CONTENTS xiii 

Page 

The Structure of Conifers 114 

Procedure in Identifying Wood 115 

Key for the Identification of Woods Used for Box and Crate 

Construction 117 

Hardwoods 117 

Conifers 122 

Description of Box Woods 126 

Hardwoods 126 

Ring-porous woods 126 

Dififuse-porous woods 128 

Conifers (non-porous woods ) 132 

Grading Rules for Rotary Cut Box Lumber 137 

Other species 138 

APPENDIX 

Names and Description of Grades of Lumber Suitable for Packing 

Boxes 141 

Index 200 



TABLES 

Page 

Factors determining amount of strength required in crates.... 85 
Table 1.— Box Woods, Consumption by Box Manufacturers, and 

Total Lumber Production 3 

Table 2.— Box Lumber Consumption and Total Lumber Production 

by States 6 

Table 3.— Quantities of Principal Woods Used Annually by Box and 

Crate Manufacturers in the Most Important States 7 

Table 4.— Approximate Weights of Lumber per Cubic Foot, and per 
Square Foot of Usual Thicknesses Used in Packing 
Boxes, Thoroughly Air-Dry (12 to IS per cent moisture), 

and Estimated Shipping Weights 12 

Table 5. — Per Cent of Shrinkage Across the Grain . 23 

Table 6. — Physical and Mechanical Properties of Woods Grown in 

the United States 27 

Table 7. — Some Physical and Mechanical Properties of Box Woods 

on the Basis of White Pine 28 

Table 8. — Thicknesses of Box Boards Obtained by Resawing or Dress- 
ing 4/4 to 7/4-Inch Lumber 40 

Table 9.- — Standard Thicknesses of Hardwoods 41 

Table 10. — Holding Power of Nails in Side and End Grain of Various 

Species SD 

Table 11. — Effect of Size of Heads on Strength of a Nailed Joint.... J7 

Table 12. — Resistance to Withdrawal of No. 12 Screws 59 

Table 13. — Size of Nails for Crating 83 

Table 14. — Size of Bolts for Crating 84 

Table IS. — Cement-coated Coolers or Standard Nails and Sinkers or 

Countersunk Nails 139 

Table 16. — Cement-coated Box Nails 140 

Table 17. — Miscellaneous Cement-coated Nails 140 

PLATES 

Plate L — Defects recognized in the commercial grading of 

lumber 163 

Plate II. — Cubes of wood magnified about 25 diameters... 164 

Plate III. — Styles of wooden boxes, nailed and lock-corner con- 
struction 167 

Plate IV. — Special styles of boxes 169 

Plate V. — Strapped boxes 171 

Plate VI. — Types of handles 173 

Plate VII. — Different types of corner construction 175 

Plate VIII. — Wirebound boxes 177 

Plate IX. — -Types of commercial boxes 179 

Plate X. — Types of plywood or veneer panel boxes 181 

Plate XL — Three-way crate corners 183 

Plate XII. — Various arrangements of crate members at three-way 

corner 185 

Plate XIII. — Crates with special features 187 

Plate XIV. — Method of numbering faces of test boxes and crates 
for convenience in recording data and location of 

failures 189 

Plate XV. — Different kinds of joints and fasteners 191 



XV CONTENTS 

Page 

Plate XVI.^Hardwoods with pores 193 

Plate XVII. — Diffuse-porous hardwoods 194 

Plate XV^III. — Softwoods, conifers, or woods without pores or vessels 197 
Plate XIX. — Split tangential surfaces of Sitka spruce and Douglas 

fir 198 

FIGURES 

Fig. 1. — Annual lumber consumption by States for the manufacture of 

boxes, crates, fruit and vegetable packages 4 

Fig. 2. — Relation of moisture content of wood to relative humidity... 17 
Fig. 3. — Relation between the volumetric shrinkage and specific gravity 

of various American woods 18 

Fig. 4. — Cupping of lumber 20 

Fig. 5. — Efifect of moisture upon the strength of small clear specimens 

of Western hemlock 21 

Fig. 6. — End of honeycombed oak plank 23 

Fig. 7. — Collapse in 1-inch boards 24 

Fig. 8. — Method of measuring twisting of plywood 32 

Fig. 9. — Lumber piled sidewise on concrete and metal foundations.... 33 
Fig. 10. — A well-kept lumber yard maintained by a large Eastern wood- 
using factory 34 

Fig. 11. — Side view of' lumber piled endwise to the alley with skids 

resting directly on the piers 34 

Fig. 12. — Efifect of condition and change of condition of lumber on 
strength of boxes in storage. Boxes for 2 doz. No. 3 cans, 
nailed with seven cement-coated nails to each nailing edge. . 46 
Fig. 13. — -Effect of shrinkage on strapped boxes. Boxes made and 
strapped at a 30 per cent moisture content ; the boxes were 
photographed after drying out to 10 per cent moisture 

content 47 

Fig. 14. — Division of a beam into volumes for describing the location of 

knots 48 

Fig. 15.— Broken crating of ornamental concrete lighting post 49 

Fig. 16. — Efifect of time on the holding power of nails 52 

Fig. 17. — Details for nailing standard styles of boxes for domestic 

shipment 54 

Fig. 18. — Relation of number of nails to amount of rough handling 
required to cause loss of contents. Nailed boxes for 2 doz. 

No. 3 cans 56 

Fig. 19. — Iniury to wood fiber resulting from overdriving nails 56 

Fig. 20. — Effect of overdriving nails 58 

Fig. 21. — Nailed box showing panel style of construction 69 

Fig. 22. — Box with corrugated fiber board lining and cells 75 

Fig. 23. — Testing boxes in small revolving drum developed at Forest 

Products Laboratory 88 

Fig. 24. — Standard large drum testing machine developed at Forest 

Products Laboratory 89 

Fig. 25. — Method of making drop-cornerwise test 90 

Fig. 26. — Method of making compression-on-an-edge test 93 

Fig. 27. — Method of making compression-cornerwise test 94 

Fig. 28. — Method of making compression-on-faces test 95 

Fig. 29. — Section of Western yellow pine log Ill 

Fig. 30. — Forest regions of the United States 125 



II 



WOODEN BOX AND CRATE CONSTRUCTION 

CHAPTER I 

THE USE OF WOOD IN BOX AND CRATE 
CONSTRUCTION 

Commercial Grades and Sizes of Lumber Available for Box 
Construction — Important Physical Properties of 
Wood Which Influence Its Use in Box Construction 
— Mechanical or Strength Properties of Wood— Care 
and Seasoning of Lumber in Storage — The Use of 
Veneer in the Construction of Packing Boxes. 

Adaptability 

Availability — Although our forest resources are rapidly 
diminishing, lumber is still the most abundant material 
economically suitable for the manufacture of packing boxes 
and crates. The lower grades of lumber are used almost ex- 
clusively for this purpose and are sure to be abundant for 
many years to come. The closer utilization of virgin timber, 
especially of the small and defective trees and of the tops, and 
the cutting of second and third-growth timber, which is 
nearly always of poorer quality, make a large amount of 
low grade lumber available. Thus, in the eastern section of 
the United States, cut-over or second-growth forests furnish 
the greater part of the supply of logs, and these logs furnish 
a large amount of low grade lumber, so that the percentage 
of low grades manufactured from southern yellow pine, hem- 
lock, and northern pine has increased rapidly during recent 
years. 

Cost — The large amount of low-grade lumber manufac- 
tured has kept the cost comparatively low. And the increase 
in cost of rotary-cut lumber or veneer, caused by the neces- 
sity of using better logs than for other kinds of box lumber, 
is offset by the thinness of the material and the compara- 
tively small waste in cutting. 

Salvage Value — Wooden packing boxes have consider- 
able salvage value, as is indicated by the ready sale mer- 



2 WOODEN BOX AND CRATE CONSTRUCTION . 

chants have for such material. Some large mercantile con- 
cerns rebuild their used boxes to store goods in or to use for 
shipping purposes. Whenever boxes are used over again 
for shipping, special precautions should be taken to make 
sure that they are in fit condition for transportation. Many 
of the claims for damaged freight are due to the use of 
second-hand boxes in imperfect condition. Other purposes 
to w^hich used packing boxes are put are commonplace. 
Quite often the box is taken apart and the lumber used for 
repairs or light construction w^ork. Considerable kindling is 
often obtained from the dump pile of boxes in the merchant's 
back yard. 

Qualities 

Desirable Qualities — AVood possesses the following 
properties desirable in the manufacture and subsequent use of 
packing boxes and crates : 

1. It is strong for its weight. 

2. It is easily worked. 

3. It is easily fastened together. 

4. It is not easily indented or bent out of shape. 

5. It is not corroded by sea water or attacked by acids 
unless they are of high concentration. 

6. It is a poor conductor of heat, which is of service in 
protecting certain contents of packing boxes when stored for 
a relatively short time exposed to the sun's rays, to heat from 
steam pipes or boilers, or to freezing temperatures. 

7. It takes and holds ink well, so that addresses and 
advertising can be stenciled or printed on it without difficulty. 

8. When its usefulness is ended and it becomes refuse, 
it can be easily disposed of. 

KINDS AND AMOUNTS OF LUMBER USED 

The Choice of Species — The choice of species for boxes 
and crates is influenced chiefly by cost and availability, the 
tendency being usually to make selection out of kinds of lum- 
ber that are comparatively cheap and readily available in the 
locality where the manufacturing plant is situated ; but, in 
addition, the degree in which the desirable qualities listed 
above are present is also considered, together with re- 
sistance to shearing out of fastenings at the end of boards, 
the commodities to be packed, and the comparative freedom 
from odor and taste. 



USE or WOOD IN BOX AND CRATE CONSTRUCTON 3 

Table 1. Box Woods, Consumption by Box Manufacturers, and Total 
Lumber Production 



Kind of wood 



Quantity used 

annually by box 

manufacturers 

(1912) 



Feet 
board measure 



Total lumber 

production' 

(1918) 



Feet 
board measure 



White pine 

Yellow pine (including North Carolina 

pine) 

Red gum (including sap gum) 

Spruce 

Western yellow pine 

Cottonwood 

Hemlock 

Yellow poplar 

Maple 

Birch 

Basswood 

Beech 

Tupelo 

Elm 



1,131,969,940 



Oak 

Balsam fir 

Cypress 

Chestnut 

Sugar pine 

Sycamore 

Ash 

Willow _. 

Larch (including tamarack) 

Douglas fir 

Noble fir 

Magnolia 

Buckeye 

White fir 

Cedar 

Redwood 

Red fir 



All other woods 



1,042 

401 

335 

288 

210 

203 

165 

96 

90 

86 

77 

74 

63 

56 

40 

38 

36 

24 

16 

10 

10 

7 

7 

6 

5 

3 

3 

2 

2 

1, 



936,123 
735,390 
935,643 
691,927 
819,509 
526,091 
116,737 
831,648 
787,900 
979,611 
899,280 
982,910 
726,458 
362411 
173,700 
962,895 
216,700 
686,000 
451,693 
507,308 
004,600 
470,300 
349,840 
653,500 
449,000 
174,028 
142,080 
512,150 
439,500 
328,330 



3,150,278 



2,200,000,000 

10,845,000,000 

765,000,000 

1,125,000,000 

1,710,000,000 

175,000,000 

1,875,000,000 

290,000,000 

815,000,000 

370,000,000 

200,000,000 

290,000,000 

237,000,000 

195,000,000 

2,025,000,000 

82,000,000 

630,000,000 

400,000,000 

111,800,000 

30,000,000 

170,000,000 

6,269,000 

355,000,000 

5,820,000,000 

5,201,000 

1,579,000 

3,646,000 

213,000,000 

245,000,000 

443,231,000 

Included in 

white fir 

60,963,000 



Total 4,547,973,180 31,694,689,000 



Amount of Each Kind of Lumber Used" — The woods 
used for boxes, the amounts, and the total annual production 
of lumber of each species are given in Table 1. The figures 
on the consumption of box lumber are those secured by a 



'Computed total productions. For details see U. S. Department of Agriculture 
Bulletin 845, "Production of Lumber, Lath, and Shingles in 1918." 

-The explanation of Tables 1, 2 and 3, and the information contained in Table 
5 were taken principally from a mimeoRraphed circular, "Packing Box Woods: 
Kinds, Supply, Distribution, Grades and Sizes Available," prepared by J. C. Nellis, 
formerly Forest Examiner in the Forest Service, U. S. Dept. Agriculture. 



WOODEN BOX AND CRATE CONSTRUCTION 




USE OP WOOD IN BOX AND CRATE CONSTRUCTON 5 

series of studies of the wood-using industries by States, made 
by the Forest Service from 1909 to 1913. The information, 
however, is not complete owing to the fact that a number 
of mills did not report their consumption. It is estimated 
that today the amount of lumber used annually in the manu- 
facture of shipping containers is between five and six billion 
feet, or nearly one-sixth of the total lumber cut in the United 
States. While the figures in the table apply to different years, 
all are based on a period of 12 months. They may be said 
to apply to 1912 as an average year. 

The figures on the total production of (liffcrent species 
are for 1918, the latest available at this time. 

In compiling statistics it has been found best to combine 
some of the different species or kinds of woods because of 
the confusion on • the part of manufacturers as to species. 
Some of the names listed in Table 1 cover a number of 
species. 

Consumption of Box Lumber by States — The total 
amount of wood consumed in each State by box manufac- 
turers and the total lumber cut of each State arc given in 
Table 2. This is shown graphically in figure 1, in which 
the size of the squares in each State represents the relative 
total consumption of wood for boxes, crates, and fruit and 
vegetable packages. The statistics used in Table 2 come 
from the same source as those in Table 1. Table 3 shows 
the principal woods used in the important box manufactur- 
ing States. This table is limited to include only the 24 most 
important box manufacturing States and the 19 most im- 
portant species ; but the 24 States are located in all parts of 
the country, so that the table shows what woods are most 
used in every part of the United States. 

Distribution of Box Lumber — Some of the largest box 
manufacturing States produce but little of the lumber so 
used. In this class are Illinois, Pennsylvania, and New 
York. Other States which are of medium rank in the box 
industry, but produce very little box lumber, are New Jersey, 
Maryland, Ohio, and Indiana. 

From the region south of the Ohio and Potomac Rivers 
box lumber moves northward to consuming points in two 
general currents, separated by the Appalachian Mountains ; 
that is. North Carolina pine from Virginia and the Caro- 
linas goes northward east of tlie Allegheny Mountains, while 
from the Central and (Julf States yellow pine, red gum, etc., 



WOODEN BOX AND CRATE CONSTRUCTION 



Table 2. Box Lumber Consumption and Total Lumber Production 

BY States 



State 



Quantity used 

annually for boxes 

(1912) 



Feet 
board measure 



Total lumber 

production 

(1918) 



Feet 
board measure 



Virginia 

New York 

Illinois 

Massachusetts 

California 

Pennsylvania 

Michigan '. 

New Hampshire 

Ohio 

Maryland 

Wisconsin 

Kentucky 

Missouri 

Arkansas 

Maine 

New Jersey 

Washington^ 

Indiana 

Oregon^ 

Tennessee 

Minnesota 

North Carolina 

Louisiana 

Florida 

Vermont 

Mississippi 

Texas 

Iowa 

Kansas 

Arizona and New Mexico 

Delaware 

Connecticut 

Georgia 

West Virginia 

Alabama 

Rhode Island 

South Carolina 

Idaho 

Nebraska 

Montana 

Colorado 

Oklahoma 

Nevada and Utah 

District of Columbia . . . . 
North and South Dakota 
Wyoming 

Total 



433,028,997 

390,057,650 

389,199,000 

353,405,350 

309,406,285 

276,587,094 

232,111,486 

200,209,596 

153,417,273 

144,309,000 

119,267,000 

112,424,500 

111,765,699 

110,822,000 

108,889,400 

102,605,205 

96,448,500 

85,267,160 

78,939,000 

77,979,510 

77,854,600 

76,525,000 

56,004,500 

53,469,000 

48,871,060 

39,295,093 

35,762,125 

31,340,476 

28,544,500 

28,035,000 

27,624,175 

24,411,090 

24,373,409 

23,837,000 

22,442,000 

15,951,200 

13,960,000 

10,245,000 

6,861,000 

5,249,927 

4,734,000 

4,389,000 

1,517,000 

518,655 

18,667 



4,547,973,180 



855,000,000 

335,000,000 

42,000,000 

175,000,000 

1,277,084,0001 

530,000,000 

940,000,000 

350,000,000 

235,000,000 

71,000,000 

1,275,000,000 

340,000,000 

273,000,000 

1,470,000,000 

650,000,000 

19,500,000 

4,603,123,000 

250,000,000 

2,710,250,000 

630,000,000 

1,005,000,000 

1,240,000,000 

3,450,000,000 

950,000,000 

160,000,000 

1,935,000,000 

1,350,000,000 

14,200,000 

8,401,000 

172,576,000 

6,000,000 

64,000,000 

515,000,000 

720,000,000 

1,270,000,000 

13,100,000 

545,000,000 

802,529,000 

none 

340,000,000 

56,882,000 

195,000,000 

9,815,0003 

none 

29,533,000* 

7,501,000 



31,890,494,000 



^California and Nevada. 

-1914 .statistics on box lumber consumption are available: Washington, 
307,980 feet board mieasure ; Oregon, 72,299,344 feet board measure. 
^Utah only. ^South Dakota only. - 



USE OF WOOD IN BOX AND CRATE CONSTRUCTON 



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move approximately straight northward. Material from the 
Lake States, principally Minnesota, Wisconsin, and northern 
Michigan, moves to northern Illinois and Indiana. Canadian 
white pine goes into Michigan, northern Ohio, and western 
New York. New England is to a considerable extent self- 
supporting ^s regards box lumber, although considerable 
North Carolina pine gets into Connecticut and Rhode Island 
and some Canadian white pine goes into northern New Eng- 
land. The Western Pacific States are not only self support- 
ing but at times supply considerable material to the territory 
east of them. Some box material is shipped from Arizona 
and New Mexico, principally to the middle west. Mexican 
pine is used by some of the box factories on the Mexican 
border. 

As the outcome of conditions resulting from the war, 
many of the different species may now be found in markets 
far removed from their regions of growth, e. g., white pine 
from New England is manufactured into boxes in Texas 
and spruce from Oregon and Washington in Massachusetts. 

COMMERCIAL GRADES AND SIZES OF LUMBER AVAIL- 
ABLE FOR BOX CONSTRUCTION 

Standard Defects and Blemishes in Lumber 

Commercial lumber grades are based on the number, size, 
and position of the defects and blemishes the lumber contains, 
and, to a certain extent, on the size of the pieces. 

Defect — A defect is any irregularity occurring in or on 
wood that may lower som"e of its strength values. 

Blemish — A blemish is anything not classified as a de- 
fect which mars the appearance of the wood. 

The following are the principal recognized defects and 
blemishes in lumber which may lower its graded (See also 
Plate I.) 

1. Knots — Knots are irregularities of growth caused by 
the junction of a branch with the body of a tree. These are 
further classified as to size, shape, and quality. 

A pin knot is less than }^ inch in diameter. 

A standard knot is from ^ to 1^^ inches in diameter. 

iThe definitions of defects as here given are not universally accepted. For 
example, a standard knot, according to the West Coast Lumbermen's Association, 
is from % to 1% inches in diameter ; under the rules of the Southern Cypress Manu- 
facturers' Association a standard knot is from % to 1% inches in diameter ; and 
according to the two hardwood associations a knot l^/t inches in diameter is con- 
sidered a standard defect. At the present time, standard definitions of terms re- 
lating to defects and blemishes are being revised by the National Association of 
Lumber Manufacturers. 



USE OF WOOD IN BOX AND CRATE CONSTRUCTON 9 

A large knot is over Ij^ inches in diameter. 

A round knot is circular or oval in form. 

A spike knot is cut through lengthwise, and, therefore, 

can occur on quartcr-sawcd surfaces only. 
A sound knot is as hard as the wood it is in, and is so 

tixcd by growth or position that it will retain its place 

in the piece. 
An encased knot is not firmly connected throughout with 

the surrounding wood. If intergrovx^n partially with 

the surrounding wood or so held by shape or position 

that it will retain its place in the piece, it is considered 

a sound knot. 
A water-tight knot is completely intergrown with the 

surrounding wood on one face, and is sound on that 

face. 
A loose knot is not firmly held in position ; it may drop out. 
A pith knot is a sound knot with a hole not over % inch 

in diameter at the center. 
A rotten knot is not so hard as the wood it is in. 

2. Shake — Shake is a partial or entire separation of the 
wood between annual rings. 

3. Checks — Checks are splits which run radially across 
the rings. They are usually due to unequal shrinkage in 
seasoning. 

4. Splits — Splits are due to rough handling or internal 
stresses and are easily confused with checks and shakes. 

5. Pitch Pockets — Pitch pockets are lens-shaped open- 
ings between the annual rings of some conifers and contain 
more or less pitch or bark. 

6. Pitch Streaks — Pitch streaks are conspicuous accumu- 
lations of pitch in the wood cells. 

7. Wane — Wane is bark on the edge of a piece or the 
absence of the square edge. 

8. Rot and Dote — Rot and dote refer to different stages 
of decay due to wood-destroying fungi. Either is permissible 
to a certain extent in the lower grades of lumber. 

9. Stain — Stain (as blue stain, brown stain, water stain, 
and others not due to decay) usually affects only the ap- 
pearance of lumber and is not considered a defect in the lower 
grades. 

10. Pith — Pith is the small soft core at the structural 
center of a log. It is often surrounded by small checks, 



10 WOODEN BOX AND CRATE CONSTRUCTION 

shakes, numerous pin knots, etc. In some woods it is large 
enough to be objectionable on the face of lumber. 

11. Worm Holes — Worm holes are very common in 
some woods and may render them' unfit for high-grade work. 
They may be small, in which case they are known as pin- 
worm holes, or if in groups, shot- worm holes ; or they may 
be large, in which case they are known as grub-worm holes. 

12. Bird Pecks and Gum Spots — Bird pecks and gum 
spots appear as brown or black discolorations. Sometimes 
an open cavity is formed, which in the case of gum spots 
may contain a gum-like substance. 

13. Rafting Pin Holes — Rafting pin holes may be bored 
for rafting pins or holes made by driving rafting pins into 
the wood. 

14. Warping — Warping includes both twisting and 
cupping and is due mostly to improper piling and drying 
methods and may cause clear lumber to be put in a low grade. 

15. Crook — A crook is the curving of a piece edgewise 
in the longitudinal direction. 

16. Bow — A bow is the deviation of a piece flatwise. 

17. Twisting — Twisting is the turning or winding of 
the edges of a piece so that the four corners of a face are no 
longer in the same plane. 

18. Cupping — Cupping is the curving of a piece across 
the grain or width of the piece. 

19. Poor Manufacture — Poor manufacture, as irregular 
width or thickness or chipped or torn grain, is cause for 
putting lumber in a lower grade. 

Grading According to Size of Lumber 

Standard Sizes of Lumber — The sizes of lumber avail- 
able to the box manufacturer are, in general, the same as are 
made for the general lumber trade. The thicknesses used are 
normally in the rough, 4/4, 5/4, 6/4, 7/4, and 8/4 inches. These 
thicknesses are resawed in the box factory to produce 1/4, 
5/16, 3/8, 7/16, 1/2, 9/16, 5/8, 11/16, 3/4, and 13/16- 
inch material surfaced on one side or scantily surfaced on 
two sides. The widths range from about 3 or 4 inches up 
to about 12 inches, or sometimes up to 16 inches. In some 
woods, stock widths only are manufactured, that is, even-inch 
widths (4, 6, 10, and 12, etc., inches) ; in other woods, both 
stock and random sizes (odd inch and fractional inch widths) 



USE 01' WOOD IN BOX AND CRATE CONSTRUCTON 11 

are made ; in hardwoods, random widths only are standard, but 
they are measured to the nearest whole inch. Lengths of box 
lumber generally range from 1 to 20 feet. Regular grades are 
often cut from 6 or <S feet up to 16 or 20 feet ; while a special 
grade, usually known as short box, includes the shorter 
lengths. 

Much of the lumber cut in the New England States is 
not edged at the mill but is put on the market in the form 
of tapering boards with waney edges. This is known as 
"round-edged" lumber and consists mostly of second-growth 
white pine, spruce, hemlock, and fir. About 10 per cent more 
box lumber can be cut from New England timber if it is not 
edged until after it is cut to lengths and if it is not edged to 
standard widths. On account of the difficulty of satisfactorily 
grading round-edged lumber, it is not graded, as a rule, but 
is sold as long run. 

Grades Suitable for Boxes and Crates — Grading rules 
for a certain species or group of woods are prepared by the 
lumbermen's associations particularly interested in that kind 
of lumber. At the present time there are a number of lum- 
ber associations which have standard grading rules. Some 
woods are graded by more than one association under rules 
which are not similar, a condition which causes more or less 
confusion in preparing lumber. Neither are the names, quali- 
ties, or sizes of similar grades of the different associations 
always alike. 

The upper grades, which contain fewest defects and a 
very limited per cent of narrow widths and short lengths, are 
seldom used in the manufacture of shipping containers. The 
low grades, which contain more or less knots and other de- 
fects, furnish the material commonly used. 

The problem of the manufacturer is to cut out the de- 
fects not permissible in the kind of boxes he is making and 
to do this with as little waste as possible and with the least 
expenditure of power and labor. In general, the waste of 
lumber in making boxes is from 15 to 20 per cent. Insistence 
upon boxes finished without knots would result in a much 
larger waste or in the use of a finishing grade. Because of 
the cost of lumber and labor, box specifications should permit 
the use of low grades and cause as little waste in working 
up the lumber as is consistent with the box requirements. 



12 



WOODEN BOX AND- CRATE CONSTRUCTION 



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14 WOODEN BOX AND CRATE CONSTRUCTION 

IMPORTANT PHYSICAL PROPERTIES OF WOOD WHICH 
INFLUENCE ITS USE IN BOX CONSTRUCTION 

Weight 

Importance — The weight of the wood used for packing 
boxes and crates is very important. It influences the cost of 
both handling and transportation. The strength, shrinking, 
and warping of lumber, and the ease with which it splits in 
nailing increase, as a rule, with the dry weight. Where 
strength is an important factor, light pieces, no matter what 
the species may be, should not be used. Thinner pieces may 
be used of the heavier woods than of the lighter woods, 
without reducing the strength. The denser woods hold nails 
better and are desirable on this account. On the other hand, 
the lighter woods give less trouble in seasoning and manu- 
facture. 

How the Weight of Lumber is Expressed — In commer- 
cial practice the weight of lumber is usually expressed in 
pounds per thousand board feet when "shipping-dry." This 
ranges from about 2,100 pounds for very light woods to over 
4,000 pounds for very heavy woods. A more definite way of 
expressing the weight of wood is in pounds per cubic foot 
or per square foot of specified thickness at any given mois- 
ture content or degree of seasoning, as green, thoroughly air 
dry, kiln dry, or oven dry. For the convenience of box de- 
signers and manufacturers the approximate weights for dif- 
ferent thicknesses of box lumber and veneer are given in 
Table 4. 

The weight is often expressed in terms of specific grav- 
ity, which means the ratio of the weight of an object to the 
weight of an equal volume of water. '^ To determine the 
specific gravity of wood, it is customary to use the oven-dry 
weight and the volume measured while the wood is in the 
same condition or when green or partly dry. It should always 
be stated under what moisture condition the weight and 
volume were measured. Table 4 gives the specific gravity 
of box woods. 

Factors Which Influence the Weight of Lumber 

1. Species — A great variation is found in the weight of 
the various commercial species, as can be seen from Table 4. 



I 



^A cubic foot of water weighs approximately 62.5 pounds. 



VSE OF WOOD IN BOX AND CRATE CONSTRUCTON 15 

2. Density, or Amount of Wood Substance — Even in 
the same species there is considerable variation in weight 
due to differences in density (the figures given in Table 4 are 
only average, or approximate). Species growing in the wet 
swamps of the South show the greatest variation. The 
swelled butt logs of trees growing in places where the 
ground is covered with water a large part of the year usually 
contain very light wood. Higher up in the tree the wood is 
denser and heavier. Very light pieces of cotton gum 
(tupelo), cypress, and ash usually come from such localities. 
Ordinarily, however, butt logs produce the heaviest wood. 

3. Moisture Content — The moisture in kiln-dry wood 
adds only about 5 or 10 per cent (occasionally more) to the 
weight, but in green wood the water contained may weigh 
more than the wood itself. Thoroughly air-dry wood usually 
contains from 12 to 15 per cent moisture. 

4. Resin Content — In yellow pine, Douglas fir, tama- 
rack, and occasionally in spruce, parts of the tree trunk be- 
come infiltrated with resin to a considerable extent. "Fatty 
pieces," as such resinous pieces are called, are considerably 
heavier than normal wood. 

Moisture Content 

Importance — A knowledge of how much moisture is con- 
tained in wood when manufactured and when put into use is 
exceedingly important. When boxes or shooks are manu- 
factured under certain moisture conditions and then stored 
in a warehouse or shipped to a drier or wetter climate, the 
moisture content will accommodate itself to the varied at- 
mospheric conditions. This aft'ects the shrinkmg or swelling, 
warping, checking, weight, strength, and nail-holding power 
of the wood. 

How Determined — To determine the approximate mois- 
ture content of a stack of box material : 

Select one representative piece from every 100 or 500 
pieces. In the case of lumber, sections ^ inch or less with 
the grain should be cut two or more feet from the end at 
a place free from knots, rot, or other abnormalities, and 
where sapwood and heartwood arc in representative propor- 
tions. 

Immediately after cutting these sections, pick off all loose 
slivers and weigh the samples to an accuracy t)f one-half of 



16 WOODEN BOX AND CRATE CONSTRUCTION 

1 per cent. If a delicate scale is not available, several sec- 
tions may be taken out of each piece to insure greater ac- 
curacy. This weight we will call the original weight. 

Dry the sections in an oven in v^hich an even tempera- 
ture of about 212° F. and free circulation of air over end 
grain can be maintained, until they no longer lose in weight. 
Sections ^ inch long will usually dry out completely over 
night. If a drying oven is not available, the samples will 
reach within 1 or 2 per cent of the same dryness when laid 
on pipes containing live steam. 

Weigh the dry samples to an accuracy of one-half of 
1 per cent and subtract this oven-dry weight from the orig- 
inal weight. Divide the difference by the oven-dry weight 
and multiply by 100. This gives the per cent moisture 
based on the oven-dry. weight. 

Thus, if the original weight is 625.7 grams and the oven- 
dry weight 438.2 grams, the moisture content is : 
625.7—438.2=187.5 grams; and 

187 5 

■ ' X 100=42.8 per cent moisture content 

Variation — In green timber the moisture content ranges 
from about 30 to 250 per cent, based on oven-dry weight. In 
so called air-dry wood it may range from 5 or 8 per cent, as 
in small pieces, to over 30 per cent, as in timber dried to re- 
duce its shipping weight. Kiln-dry wood is also highly vari- 
able in moisture content, depending on the purpose for which 
it is dried and the care with which the drying is carried on. 
If the object of the drying is to reduce quickly the shipping 
weight, the lumber may be no drier or not even so dry as it 
would become from prolonged air drying. On the other hand, 
lumber may become too dry in a kiln and give trouble during 
and after manufacture. 

How the Moisture is Contained in Wood — The troubles 
from shrinking, swelling, warping, and cupping of lumber 
when put into use arise from the manner in which the mois- 
ture is held in the wood. It is held principally in two ways, 
(1) filling the cell cavities and (2) absorbed in the cell walls. 
When wood dries, the moisture first leaves the cell cavities, 
and after they are empty it begins to leave the cell w^alls. 
The condition in which the cell cavities are empty but the 
cell walls still fully saturated is known as the "fiber-satura- 
tion point." As a rule wood does not shrink in drying or lose 
in strength until the moisture content falls below the fiber- 



USE OF WOOD IN BOX AND CRATE CONSTRUCTON 17 

saturation point. This niuisturc content ran<;'cs from 20 to 35 
per cent. The moisture content of seasoned lumber does not 
remain constant but varies with the humidity of the surround- 
ing atmosphere. This is due to the cell walls giving off or 
absorbing moisture. (The curve in figure 2 shows the mois- 




Curves showiiiK the moisture content of wood 
when at e(|uilibriuin with atmospheric conditions 
of various humidities and three different tem- 
peratures. 

Curve A, based on the average of five species. 
(Data by M. E. Dunlap.) 



10 20 30 40 ' 50 60 70 80 90 100 

Fig. 2 — Relation of inoisture content of wood to relative humidity. 

ture content at which wood will ultimately arrive under a 
given humidity and various temperatures. It is based on only 
a limited number of woods but is believed to be representa- 
tive for most species.) This relation of the moisture content 
of wood to the relative humidity is of great significance in 
the manufacture and use of wooden articles. 

Proper Moisture Content of Box Lumber — The moisture 
content of wood for any purpose should be, at the time of 
manufacture, approximately what it will be when the wood is 
in use. For boxes and crates from 12 to 18 per cent is con- 
sidered a safe approximation. 

If the lumber used has too high a moisture content vari- 
ous weaknesses develop later (see page 47) ; the box will be 
heavier than necessary ; if it is made for a standard-sized ar- 
ticle, it will not fit the contents unless allowance is made for 
shrinking ; and if it is not assembled immediately, the dif- 
ferent parts may not fit together properly. 



18 



WOODEN BOX AND CRATE CONSTRUCTION 




0.1 



0.2 



0.3 0.4 0.5 

SPECIFIC GRAVITY 



0.6 



0.7 



Fig. 3 — Relation between the volumetric shrinkage and specific gravity of various 
American woods. See opposite page for list of species and reference numbers. 



USE OF WOOD !N BOX AND CRATE CONSTRUCTON 19 



HARDWOODS 

Species Locality Ref. 

Alder, red Wash 

Ash, biltmore Teiin 

black Mich 

black Wis 

blue Ky 

green I>a 

green Mo 

pumpkin Mo 

white Ark 

white N. Y 

white W. Va 

Aspen Wis 

largetooth Wis 

Basswood Pa 

Wis 

Beech Ind 

Pa 

Birch, paper Wis 

sweet "* 

yellow Pa 

yellow Wis 

Buckeye, yellow Tenn 

Buckthorn, cascara Ore 

Butternut Team 

Wis 

Chinquapin, Western Ore 

Clierry. black Pa 

Cherry, wild red Tenn 

Chestnut Md 

Tenn 

Cottonwood, black Wash 

Cucumber tree Tenn 

Dogwood (flowering) Tenn 

(Western) Ore 

Elder, pale Ore 

Elm, cork W'is., Marathon Co... 

Wis., Rusk Co. 

Elm, slippery Ind 

slippery Wis 

white Pa 

white Wis 

Greenheart 

Gum, black Tenn 

blue (eucalyptus) C'al 

cotton I/a 

red Mo 

Hackberry I"<1 

Wis 

Haw. pear ^^ 's 

Hickory, big shellback Miss 

big shellback Ohio 

Hickory, bitternut Oliio 

morkernut Miss 

mockernut Pa 

ninckernut W. Va 

nutmeg Miss 

pignut Miss 

pignut Ohio 

pignut Pa. ^ 

pignut W. Va 

shagbark Miss 

shagbark Ohio 

shagbark Pa 

shagbark W, Va 

water Miss 

Holly. American Tenn 

Hornbeam Tenn 

Laurel, niomitain X^"" 

Locust, black ^^nn 

honey Jl"" 

Madrona l^al 

Ore 

Magnolia, J;?-- • 

Maple, Oregon wash 

red Pa 

red Wis 

silver Wis 

sugar Ind 

sugar Pa 

sugar W'is 

Oak, burr Wis 

California black C'al 

canyon live Cil 

chestnut Tenn. . . 

Cflw La 

laurel La 

post Ark. . , . 

post La 

red Ark. . . . 



No. 

30 

91 

60 

70 

99 

93 
100 

79 
106 
128 

83 

23 

20 

12 

3 

110 

98 

73 
129 
107 
103 
9 

84a 

27 

21 

4eb 

72 

24 

46 

40 
6 

59 
151 
125 a 

6fla 
126 
120 
102 

74 

55 

53 
165 

68 
147 

76 

54 



112 
148 
157 
160 
161 
140 
152 
143 
153 
141 

R7 
148 
145 
158 
162 
101 
128a 

66 

58 

69 

92 

56 
104 
108 
124 
125 

80 
163 
121 
133 
116 
130 
137 
119 



Species Locality Ref. No. 

Oak. red Ind 118 

red La 117 

red Tenn 97 

Highlaad Spanish La 94 

Lowland Spanish La 142 

swamp white Ind 150 

tanbark Cal 115 

water La Ill 

white i Ark 132 

white Ind 138 

white La., Richland Parish... 136 

white La., Winn Parish 131 

willow La 109 

yellow Ark 122 

yellow Wis 105 

Osage orange Ind 164 

Poplar, yellow (tulip-tree) . ..Tenn .... 35 



Rhododenron, great Tenn. 

Sassafras Tenn. 

Serviceberry Tenn. 

Silverbell-tree Tenn. 

Sourwood Tenn. 

Sumac, staghorn Wis. 

Sycamore Ind. 

Tenn 65 

Umbrella, Fraser Tenn 45 

Willow, black Wis 11 

W' illow. Western black Ore 43a 

Witch hazel Tenn 114 



. 85 
, 51 
,156 
. 49 
. 89 
. 61 
63 



CONIFERS 



Speed es 



locality Ref. No. 



Cedar, incense Cal 26 

Western red Mont 2 

Western red Wash 10 

white Wis 1 

ivpre.s.s. bald La 62 

Fir, Alpine Colo 4 

amabilis Ore 39 

amabilis Wash '18 

balsam Wis 14 

Douglas Oal 45a 

Douglas Ore 67a 

Douglas Wash, aaid Ore 67 

Douglas Wash. , I>e\vis Co 75 

Douglas Wash., Chehalis Co. . 46a 

Douglas Wyo 48 

grand Mont 36 

noble Ore 16 

white C'al 17 

Hemlock, black Mont 47 

Eastern Tenn 52 

Eastern Wis 15 

Western Wash 50 

Larch, Western Mont 84 

Western Wash 64 

Pine, Cuban Fla 127 

jack W'is 43 

.Jeffrey Cal 33 

loblolly Fla 88 

lodgepole Colo 31 

lodgepole Mont.. Gallatin Co.. 35a 

lodgepole Mont.. Granite Co.. 41a 

lodgepole Mont.. .Tefferson Co.. 40a 

lodgepole Wvo 34 

longleaf ;„■ -^^^ 1^3 

longleaf La., Tangipahoa Parish 96 

longleaf La,, Lake Charles. .. .113 

longleaf Miss 95 

Norway Wis 57 

pitch Tenn 71 

pond Fla 86 

shortleaf Ark 77 



sugar 



.Cal. 



22 



Table Moimtain Tenn. . . 

Western white Mont 42 

Western yellow Arii 19 

Western Cal 37 

Western Colo 41 

Western Mont 32 



wliite Wis. 

Redwood Cal. . Albion . . 

Cal.. Korbel.. 

Spruce, Engelmann .Colo., San Micuel Co. 

Encelmann .Colo., Grand Co 

red N. H 

red Tenn 

white N. H 

white Wig. 

Tamarack Wis 

Yew, Western Wash 



25 

28 

13 

3 

8 

44 

29 

7 

38 

81 

134 



20 



WOODEN BOX AND CRATE CONSTRUCTION 



If the lumber is too dry, it splits more easily during 
manufacture and in nailing, and is slightly more difficult to 
work; and, although the strength of the wood is greater, the 
assembled box is considerably weaker than one of the proper 
moisture content.^ Furthermore, the wood will swell later, 





Fig. a — Cupping of lumber 

A. Cupping of the two halves of a resawed board. 

B. Cupping of plain-sawed lumber while seasoning. 

bulging and wajrping, which will result in extra strain dn the 
nails, sometimes bending or withdrawing them. If the shooks 
are stored in a knock-down condition they may not fit closely 
together when later assembled. 

Dry wood is stronger in most respects than green wood 
of the same quality. The increase begins as soon as the wood 
dries to below the fiber-saturation point. No allowance, how- 
ever, for increase in strength above that of green material 
should be made for large dimension stock used for skids for 
crates, etc., because very often these are not below the fiber- 
saturation point in the interior and seasoning checks may 
develop which counteract any increased strength of the fibers 
due to seasonins:. 



^This is discussed in greater detail in Chapter II, page 47. 



USE OF WOOD IN BOX AND CRATE CONSTRUCTON 21 




Variations Due to Changes 
in Moisture Content 



Moisture 
Percent 


Crushing 
Strengtti 
atMax.Load 


iViodulus 

of 
Rupture 


IViodui^JS 

of 
Elasticity 


Green * 


1.00 


1.00 


1.00 


30 


1.04 


1.03 


1.01 


25 


1.25 


1.19 


1.10 


20 


1.48 


1.36 


1.17 


15 


1.77 


1.55 


1.25 


10 


2.19 


1.78 


1.31 


5 


2.76 


2.08 


1.37 





3.45 


2.40 


1.42 



31% and above 



X 30 Beams 



5 10 15 20 25 30 35 40 45 50 

MOISTURE PERCENTAGE BASED ON DRY WEIGHT 

Fig. S — Effect of moisture upon the strength of small clear specimens of 

western hemlock. 



22 WOODEN BOX AND CRATE CONSTRUCTION 

The various strength properties of wood do not increase 
in the same proportion as wood seasons. This is shown for 
western hemlock in figure 5. In the case of shear along the 
grain, wood very often fails to show large increase in strength 
as it dries, probably because of the checks which form in 
shrinking. The shock resisting ability shows no appreciable 
increase in most woods and decreases slightly in many species 
while seasoning. 

There is more or less prejudice against kiln-dried lumber 
for use where strength is essential. There is no doubt that a 
large amount of lumber is damaged by irtiproper methods of 
kiln drying. However, properly kiln-dried material is just as 
strong as similar lumber air-dried to the same moisture con- 
tent, and may be even stronger. 

Shrinking and Swelling of Wood 

Extent — When green or soaked wood dries it does not 
shrink until it gets down to about 25 to 30 per cent moisture 
(fiber-saturation point) and from there on it shrinks until the 
oven-dry condition is reached. Conversely, when dry wood 
absorbs moisture it swells until the fiber-saturation point is 
reached and beyond that there is no more change in dimen- 
sions, although absorption may continue, increasing the 
weight. Therefore, about half of the total possible shrinkage 
has taken place when wood is seasoned down to 12 or 15 per 
cent moisture, which corresponds to the thoroughly air-dry 
condition (see figure 6). Lumber which is only partly sea- 
soned or which is "shipping-dry" when received in the fac- 
tory, may not have shrunk appreciably, and considerable 
shrinkage may take place during and after manufacture. 

The total shrinkage from the green to the oven-dry con- 
dition varies greatly for the diiTerent species of woods, but in 
general it increases with the weight of the wood. Figure 3 
shows the. relation of shrinkage in volume to specific gravity. 

The shrinkage along the grain is so slight as to be neg- 
ligible for most purposes. Across the grain, however, it is 
considerable ; and it is decidedly less radial than tangential 
in the same piece of wood. This is shown in Table 5. 

Occasionally, what appears to be abnormal shrinkage 
takes place in drying certain kinds of lumber. The surfaces 
of such lumber have a caved-in or corrugated appearance 
when dried. (See figure 7.) Shrinkage in some species is 
more likely to occur when the wood is kiln-dried from the 



^i 



USE OF WOOD IN BOX AND CRATE CONSTRUCTON 23 

saw at high temperature. In such cases, some of the cells of 
the wood collapse as the water leaves them. This does not 



Table 5. Per Cent of Shrinkage' Across the Grain 





From green or over 
30 per cent moisture 
to the oven-dry 
condition. 


From green or over 
30 per cent moisture 
to the air-dry con- 
dition — 12 to 15 
per cent. 




Very light 
woods 


Very heavy 
woods 


Very light 
woods 


Very heavy 
woods 


Radial, i. e., across the rings 

Tangential, i. e., along the 

rings 


2.6 
4.7 


6.3 
11.2 


1.3 
2.3 


3.1 
5.6 



occur in the sapwood or at the ends or edges of lumber 
where air can readily enter the wood and prevent collapse of 
the cells. 




Fig. 6 — End of honeycombed oak plank. 

How Troubles from Shrinking and Swelling May Be 
Reduced to a Minimum in Boxes 

There is practically no method of treatment by means of 
which the shrinking and swelling of wood, when exposed to 
varying atmospheric conditions, can be entirely overcome ; 
but if the following precautions are observed so far as pos- 
sible in the selection and treatment of wood, trouble from 
these sources will be reduced to a minimum. 

1. Select light woods if other requirements permit. 

2. Be sure the wood is dried to the proper moisture 
content. 

3. Use quarter-sawed lumber — this is practical only for 
special boxes. 



^ShrinkaRe is here expressed in per cent of green dimension. 



24 WOODEN BOX AND CRATE CONSTRUCTION 




Fig. 7— Collapse in 1-inch boards 



USE OF WOOD IN BOX AND CRATE CONSTRUCTON 25 

4. Use plywood, that is, thin sheets of veneer glued to- 
gether with the grain crossed. 

5. Cover the wood with oil, paint, or other protective 
coating. 

6. Avoid as far as possible storage or use of boxes under 
widely varying atmospheric conditions. 

Checking — Checking in wood is due to stresses set up on 
account of uneven shrinkage. End checking is very common 
and often can not be avoided. It is caused by the wood's dry- 
ing more rapidly at the ends than some distance from the 
ends, where drying takes place only from the sides. 

Checks on the face of lumber, known as surface checks, 
are due to the surface drying much more rapidly than the 
interior. Wood which is badly surface-checked splits more 
easily in machining and nailing. Timbers containing the pith 
will invariably check in seasoning because the shrinkage in 
the circumferential direction is greater than toward the 
center. 

Cupping — By cupping is meant the curvature of lumber 
across the grain, which gives it more or less of a trough-like 
appearance. It may be due to one side drying more rapidly 
than the other, in which case it is temporary. Permanent 
cupping takes place in plain-sawed lumber when dried with 
insufficient weight on it. In plain-sawed lumber the side to- 
ward the center of the tree shrinks less in width, thus causing 
the lumber to curve away from the center as it dries, as 
illustrated in figure 4. 

Casehardening — By casehardening is meant a condition of 
internal stress in seasoned lumber which causes it to cup in- 
wardly when resawed. (See figure 4B.) Since much box 
lumber is resawed, casehardening gives considerable trouble 
in the box industry. 

Honeycombing — In some casehardened lumber the inter- 
nal stress becomes so great that the wood is torn apart, pro- 
ducing internal checks known as "honeycomb." (See figure 
6.) These checks also extend along the medullary rays and 
may come to the surface. 

Color — The manufacturer of boxes and crates can not 
pay much attention to the color of the wood he uses. Light 
colored woods are usually preferable, however, because ad- 
dresses and advertising matter show up better than on dark 
woods. This is one reason why pine leads as a box material. 
For certain high-grade containers only white woods are used. 



26 WOODEN BOX AND CRATE CONSTRUCTION 

Odor and Taste — Containers of certain kinds of food must 
be free from odor or taste or they will taint the contents. It 
is not the purpose of this publication to discuss which foods 
are and which are not easily tainted. The following species 
of wood have a pronounced odor and should not be used for 
shipping certain classes of food : all of the cedars (including 
arborvitae), Alpine fir, yellow pine, and sassafras. 

MECHANICAL OR STRENGTH PROPERTIES OF WOOD^ 

Meaning of Strength — Strength in the broad sense of the 
word is the summation of the mechanical properties of a 
material, or its ability to resist stress or deformation. While 
such properties as hardness, stiffness, and toughness are not 
always thought of in connection with the term "strength,"^ 
they are unconsciously included when in a specific instance 
they are important. Such expressions as strength in shear, 
strength in compression, and strength as a column are very 
specific and allow little chance for confusion. (See Tables 
6 and 7.) 

Tensile Strength — The tensile strength of a material is 
measured by the resistance it offers to forces which tend to 
pull it apart. In wood, tension may be produced along the 
grain or across the grain. The tensile strength along the grain 
is many times greater than it is across the grain. It is almost 
impossible in ordinary construction to develop full strength in 
tension along the grain since the fastenings are usually in- 
adequate ; for this reason tension tests along the grain are sel- 
dom made. 

Compression Strength — The strength in compression is 
measured by the resistance a material offers to forces which 
tend to crush it. In wood, these forces niay act along the 
grain or at right angles to it. In compression parallel to the 
grain, as in a post, wood shows great strength. In compres- 
sion perpendicular to the grain, no maximum load is reached ; 
crushing takes place as the load is increased. Crushing 
strength is important in determining the size of bearing areas 
in heavy crates. 

Shearing Strength — By shearing strength is meant the 
resistance a piece of wood offers to a force which tends to 



^Various values have been combined and are given in Table 7, as strength as 
a beam or post, stiffness, shock resisting ability, and hardness. Tlie basis for de- 
riving these values is given in Table 6. 

-Methods of determining the strength values of wood are explained in Bulletin 
556, Forest Service, U. S. Department of Agriculture. 



USE OF WOOD IN BOX AND CRATE CONSTRUCTON 27 



slide one portion of it over the other portion. It varies as the 
area of the plane along- which the shear occurs. Boxes and 

Table 6. Physical and Mechanical Properties of Woods Grown 
IN THE United States 

^lanntr of Obtaining Composite Figures Used in Table 7 



Strength as a beam or post' 


Hardness! 


Values based on 


Reduction 
factor^ 


We 
Green 


ight^ 
Air-dry 8 


Values based on 


Reduction 
factor^ 


Weight^ 
Green Air-dryS 


Static bending 
M. of R.* 


1 00 

1 80 

.80 

2.8« 
2.30 


4 

2 

2 

2 
4 


1 
1 

1 

2 


Comp. perpendicu- 
lar to grain 

End hardness 

Radial hardness . . . 

Tangential 
hardness 


1.000 
.865 
.930 

.950 


4 

2 
2 

2 


2 


F. S. atE. L.5... 
Impact bending 

F. S. at E. L.5.. . 
Comp. parallel 

F. S. atE. L.5.. . 
Max. cr. str.s 


1 
1 

1 



Shock resisting ability' 


Stiffness" 


Values based on 


Reduction 
factor^ 


Weights 


Values based on 


Reduction 
factor^ 


Weight' 


Green 


Air-dryS 


Green 


Air-dry8 


Static bending 
Work to max. load 
Total work 

Impact bending 
Height of drop. . . 


1.000 
.380 

.358 


4 
2 

4 


2 

1 

2 


Static bending 
M.ofE.' 

Impact bending 
M.ofE.' 

Comp. parallel 
M.ofE.' 


1 00 
1.00 
1.00 


4 

2 
2 


2 
1 

1 





Shrinkage' 




Values Based on 


Weight' 




2 




1 







The per cent shrinkage in volume from green to oven-dry condition is based on volume when green . 

'Formulae showing relation of other properties shown in table to specific gravity (G): 
Strength as a beam or post. .20000 G 

Hardness 4300 0^.6 

Shock resisting ability 44 . 5 G^.o 

Stiffness 3000 G 

Shrinkage 26.5 G 

2Xhe reduction factor represents the average ratio of the first property, which is taken as 
unity, to the properties listed below as determined by the average of all species tested green. 

'The weight taken into account, the relative importance of the various properties included 
in the composite values, and also the greater reliability of the values based on green tests due to the 
greater amount of data. 

*M. of R.— Modulus of rupture. 
'F. S. at E. L. — Fiber stress at elastic limit. 
'Max. cr. str. — Maximum crushing strength. 
'M. of E.— Modulus of elasticity. 

*The air-dry values were reduced to 12 per cent moisture by the following approximate 
formulJE, which may be used within narrow limits: 

When moisture is under 12 per cent When moisture is above 12 per cent 



D12 



6(AD-B) + B 



D12 - 



lO(AD-B) + B 



18-M 
D12 — Value at 12 per cent moisture. 
AD — Value air-dry as tested. 
M — Per cent moisture as tested. 



22-M 



28 



WOODEN BOX AND CRATE CONSTRUCTION 



Table 7. 



Some Physical and Mechanical Properties of Box Woods, 
ON THE Basis of White Pine^ at 100 



KIND OF WOOD 



Coniferous species 
Pine, white (Pinus strobus) . . . 

Northern white cedar 

Cedar, incense 

Cedar, Port Orford 

Cedar, Western red 

Cypress, bald 

Douglas fir — Washington and 

Oregon (coast type) 

Douglas fir — Montana and 

Wyoming (mount, type) . . . . 

Fir, Alpine 

Fir, Amabilis 

Fir, balsam 

Fir, lowland white 

Fir, noble 

Fir, white 

Hemlock, Eastern 

Hemlock, Western 

Larch, Western 

Pine, jack 

Pine, loblolly ' 

Pine, lodgepole 

Pine, longleaf 

Pine, Norway 

Pine, pitch 

Pine, shortleaf 

Pine, s ugar 

Pine, Western white 

Pine, Western yellow 

Spruce, Englemann ........... 

Spruce, red, white, sitka 

Tamarack 





■a 
c c d 

tail ° 

•sjg 


tn.o 


100 


100 


100 


(0.363) 
81 


(7.9) 
87 


(7340) 
74 


91 


103 


108 


113 


147 


128 


85 


100 


96 


113 


138 


123 


125 


161 


140 


112 


130 


112 


84 


117 


82 


103 


180 


103 


92 


130 


87 


102 


133 


107 


96 


173 


106 


96 


130 


103 


106 


128 


113 


110 


151 


121 


133 


163 


137 


108 


129 


95 


139 


161 


137 


105 


144 


99 


152 


157 


164 


121 


147 


128 


129 


151 


112 


136 


146 


138 


99 


106 


98 


108 


146 


110 


105 


127 


98 


86 


129 


82 


100 


155 


103 


135 


162 


128 



100 
(363) 

79 
124 
143 

95 
132 

154 

135 

92 

96 

79 

111 

97 

116 

134 

124 

165 

122 

159 

107 

198 

125 

150 

169 

107 

98 

109 

86 

106 

142 



100 

(6.00) 

80 

92 

157 
87 

128 

135 

114 

62 
117 

85 
119 
118 

93 
115 
108 
136 
136 
160 
103 
175 
143 
162 
157 

87 
121 

97 

77 
120 
145 



100 
(1235) 
62 
89 

140 
90 

113 

151 

114 

77 

118 

93 

124 

123 

106 

101 

121 

123 

88 

131 

103 

151 

132 

103 

125 

89 

123 

94 

82 

108 

118 



crates often fail on account of nail shear at the ends of the 
boards due to lack of shearing strength in the wood. No 
values for shearing strength are given in the tables in this 
book. 

Strength as a Beam — The strength of a beam is its ability 
to support a load. The strength varies inversely as the length, 
directly as the width, and directly as the square of the height. 



^The values in columns 2 to 6 are based on composite data derived as indicated 
in Table 6. 



USE OF WOOD IN BOX AND CRATE CONSTRUCTON 29 



Table 7. 



Some Physical and Mechanical Properties of Box Woods, 
ON THE Basis of White Pine' at 100 — Concluded 



KIND OF WOOD 



Hardwood species 

Ash, black 

Ash, pumpkin 

Ash, white 

Aspen 

Basswood 

Beech 

Birch, paper 

Birch, sweet . .■ 

Birch, yellow 

Buckeye, yellow 

Butternut 

Chestnut 

Cottonwood, common. . . 

Cucumber tree 

Elm, cork 

Elm, slippery 

Elm,' white 

Gum, black 

Gum, cotton 

Gum, red 

Hackberry 

Magnolia (evergreen) . , . . 

Maple, red 

Maple, silver 

Maple, sugar 

Oak, commercial white. . 

Oak, commercial red 

Poplar, yellow 

Sycamore 

Willow, black 



Specific gravity 
oven-dry wt. 
green volume 


Shrinkage in 
volume from 
green to oven-dry 


Si 

w HI 


i 

c 

•o 

nS 
X 

164 


126 


182 


104 


134 


143 


121 


270 


144 


152 


146 


264 


99 


137 


85 


80 


90 


200 


87 


78 


150 


205 


137 


238 


130 


203 


99 


132 


162 


185 


152 


260 


152 


211 


154 


214 


90 


149 


81 


81 


99 


127 


89 


105 


109 


141 


97 


130 


102 


175 


89 


93 


121 


173 


125 


145 


158 


173 


145 


269 


134 


175 


128 


186 


120 


180 


115 


151 


127 


168 


114 


197 


125 


154 


119 


204 


122 


190 


118 


156 


134 


175 


104 


194 


127 


154 


109 


209 


134 


156 


132 


199 


121 


144 


98 


170 


154 


182 


154 


272 


162 


196 


137 


291 


155 


186 


135 


263 


102 


143 


99 


100 


126 


173 


107 


169 


96 


160 


61 


92 



u 

o.t: 

J=JD 



203 
151 
239 
134 

91 
216 
245 
257 
272 

90 
137 
120 
122 
173 
317 
272 
199 
141 
143 
170 
249 
252 
177 
162 
204 
214 
215 

94 
133 
165 



98 

94 

124 

79 

100 

120 

93 

147 

144 

89 

91 

89 

98 

139 

115 

111 

98 

94 

102 

113 

87 

108 

125 

85 

131 

120 

131 

116 

103 

55 



For instance, a 10-foot beam is half as strong as one 5 feet 
long; a plank 8 inches wide is twice as strong as one 4 inches 
wide; a board 1 inch thick is four times as strong as one 
jA inch thick, quality and the other two dimensions being the 
same in each case. 

The computed stress in the outermost fibers of a beam at 
the maximum load is known as the modulus of rupture. The 
strength of these extreme fibers, per unit of cross-sectional 
area, varies in different species and is independent of the di- 
mensions of the stick. 



^The values in columns 2 to 6 are based on composite data derived as indicated 
in Table 6. 



30 WOODEN BOX AND CRATE CONSTRUCTION 

Stiffness — By stiffness is meant the resistance a beam 
offers to bending. It varies inversely as the cube of the 
length, directly as the width, and directly as the cube of the 
height. For instance, a 5-foot beam is eight times as stiff as 
one 10 feet long; a plank 8 inches wide is twice as stiff as one 
4 inches wide ; a board 1 inch thick is eight times as stiff as 
one 3^ inch thick. 

The modulus of elasticity is a measure of the comparative 
stiffness of beams of the same dimensions but of different 
species. 

Shock-resisting Ability — Shock-resisting ability, often 
called "toughness," is important in box and crate material. 
The rough handling boxes receive makes it very desirable 
that box woods rank high in enduring shocks without break- 
ing, although this property is often sacrificed for others more 
important commercially. 

Hardness — By hardness is meant resistance to indenta- 
tion. It is important in boxes in that it indicates the ease with 
which nails may be over-driven and consequently influences 
the selection of nails with respect to size of head, and the ease 
with which label imprints may be made in the wood. 

Nail-holding Power — By nail-holding power is meant the 
maximum resistance to be overcome in pulling nails out of 
wood. If the nails are driven into the side grain of the wood 
this resistance will be greater than if they are driven into 
the end grain. (See Table 10.) 

CARE AND SEASONING OF LUMBER IN STORAGE* 

It is usually necessary at box manufacturing plants to 
keep on hand a certain supply of lumber in excess of imme- 
diate demands. Such stock requires care to prevent deteri- 
oration and to promote seasoning as much as possible. Most 
of the seasoning, however, is usually done at the sawmill so 
as to avoid paying shipping charges on the excess moisture. 
For example, if wood containing 74 parts of moisture by 
weight per 100 parts of dry wood is dried down to 16 per cent 
moisture there have been removed 58 parts, or one-third of 
the total weight, and the freight charge is reduced correspond- 
ingly. Occasionally it is necessary to dry stock further at the 
factory. 

^For a more detailed discussion of this subject see U. S. Department of Agri- 
culture Bulletin 552, "The Seasoning of Wood," by H. S. Betts, 1917 ; and U. S. 
Department of Agriculture Bulletin 610, "Timber Storage Conditions in the Eastern 
and Southern States with Reference to Decay Problems," by C. J. Humphrey, 1917. 
These may be obtained from the Superintendent of Documents, Government Printing: 
Office, Washington, D. C, at 10 cents and 20 cents, respectively. 



USE OF WOOD IN BOX AND CRATE CONSTRUCTON 31 

Possible Deterioration in Stored Lumber 

Checking at Ends and on Surfaces — Although checking 
is always a possible cause of deterioration in stored lumber, 
the woods which are most commonly used for boxes and 
crates, namely, conifers and light hardwoods, do not check so 
badly as some of the heavier hardwoods. 

Twisting and Cupping — Lumber which is not straight 
causes more or less trouble in manufacture and sets up 
stresses in the finished box when it is nailed down in a flat 
position. These difficulties can be largely avoided by proper 
piling of the lumber. 

Casehardening, Honeycombing, and Collapse — Casehard- 
ening, honeycombing, and collapse do not develop seriously in 
the air-drying of most woods used for boxes. Oak, especially 
in the South, is apt to caseharden and honeycomb when ex- 
posed to summer atmospheric conditions. 

Blue Stain or Sap Stain — Blue stain, or sap stain, is a 
blue discoloration of the sapwood. It is very common in the 
pines and red gum and occurs also in the sapwood of other 
species. Blue stain is due to a fungous growth, which lives 
on the sap in the cells, does not destroy the wood or injure its 
strength, and is objectionable only on account of the discol- 
oration it produces. Badly stained pieces may make the 
presence of decay hard to detect. 

The fungus producing blue stain may occur in the log, 
but it occurs more commonly in freshly-sawed lumber. It can 
thrive only as long as the sapwood is moist; therefore, pil- 
ing the lumber so that it will season as rapidly as possible 
greatly reduces, though it does not prevent, this discoloration. 
Blue stain makes rapid progress in green lumber during warm 
humid weather, especially when the lumber is close-piled, aS' 
it usually is in transit. Under such conditions the stain may 
penetrate all of the sapwood in a few days. Blue stain can 
be prevented by kiln-drying the lumber immediately after 
sawing; this is ordinarily done only with the higher grades, 
although some lumber mills also run the low'er grades of lum- 
ber through a kiln. Another preventive measure consists in 
dipping the lumber as it comes from the saw in an antiseptic 
solution, such as sodium carbonate. 

Decay or Rot — Decay is due to fungous growth which 
destroys the wood substance. In order that decay may take 
place, the wood must be moist and the temperature not too 



32 



WOODEN BOX AND CRATE CONSTRUCTION 



cold. Wood dried to below 20 per cent moisture, rarely de- 
cays; therefore, box lumber dried to from 12 to 18 per cent 
moisture is practically immune from decay as long as it re- 
mains in that condition. Although decay is not so rapid in 
its action as sap stain, it may seriously reduce the strength 




Fig. 8 — Method of measuring twisting of plywood. 

of some woods in 3 or 4 months during warm weather, espe- 
cially when close-piled. Decay, including the so-called dry 
rot, can be prevented in stored lumber by properly piling the 
lumber some distance above the ground. 

Insect Attack — Certain woods are subject to insect attack 
when insufficiently seasoned. The sapwood of some seasoned 
hardwoods is subject to attack by an insect known as the 
powder-post beetle. Hickory, ash, and oak are most subject 
to this injury, but butternut, maple, elm, poplar, sycamore, 
and others are also attacked. , Containers made from such 
lumber should not be used in foreign trade because some 
countries will not allow such packages to enter for fear of the 
introduction of injurious insects. 

Proper Methods of Piling Lumber in the Yard — The 
expense which it is advisable to incur in equipping a lumber 
yard for proper air seasoning of lumber depends largely on 



USE OF WOOD IN BOX AND CRATE CONSTRUCTON 33 



the permanency of its location. The small amount of addi- 
tional work required for properly piling lumber so as to 
shorten the time required for seasoning and reduce deteriora- 
tion is usually well worth while. Lumber thrown on the 
ground promiscuously, or piled on sagged foundations with 
loose projecting ends, will surely de])reciate in value in a 
comparatively short time. 




Fig. 9 — Lumber piled sidewise on concrete and metal foundations. 

A lumber yard should be well drained, and so situated 
and divided up by alleys as to reduce the cost of handling 
the lumber to a minimum. 

Box lumber is practically always piled flat ; it may lie 
with the ends of the boards toward the alley (endwise pil- 
ing), or parallel with the alley (sidewise piling), as shown in 
figure 10. In either case the piles slope from front to rear, 
away from the alley. Endwise piling is more common be- 
cause it facilitates handling of the lumber and because of the 
better visual inspection from the alley which it afifords. Side- 
wise piling has the advantage of giving better air circulation 
from side to side, and what moisture enters the piles runs 
across the boards instead of running lengthwise and accumu- 
lating under the stickers as in end-piling. 



WOODEN BOX AND CRATE CONSTRUCTION 




PiQ. 10— A well-kept lumber yard maintained by a large eastern wood- 
using factory. (Note forward pitch of stacks, treated 
ends, and general sanitary ground conditions.) 




Fig. 11— Side view of lumber piled endwise to the alley with skids resting 
directly- on the piers. 



USE OF WOOD IN BOX AND CRATE CONSTRUCTON 35 

Foundations and Skids — Strong and durable foundations 
should be provided for the lumber piles. The best kind of 
foundation consists of piers of concrete or masonry, as 
shown in figures 9 and 11. If this form of construction is not 
feasible, creosoted wooden posts, or creosoted blocks, or sup- 
ports of very durable woods may be used. Never use un- 
treated sapwood or even heartwood of non-durable woods in 
the foundations except for very temporary purposes. 

The tops of these foundations should be level in the direc- 
tion parallel to the alley but sloping from front to rear 1 inch 
for every foot. The top of the lowest foundations should be 
suf^ciently high so that, allowing for cross-pieces over the 
piers, the lumber will be at least 18 inches from the ground. 
Weeds and other obstructions to circulation should be re- 
moved from around the piles. 

The distance between piers crosswise of the pile varies 
with the thickness of skids used, but should be such as to 
avoid any sagging in the skids. 

The distance between piers parallel with the pile depends 
on whether the cross pieces, or skids, are laid directly on the 
piers, figure 10, or on beams placed on the piers parallel to 
the pile, figure 11. If the first method is used the distance 
between piers must be the same as between subsequent stick- 
ers, for the stickers must be aligned over the skids on the 
piers. This distance should not exceed 4 feet, and for lumber 
that warps easily, it must be less. If the last method is used 
in which the skids rest on strong beams laid on the piers 
parallel with the pile, fewer piers need be built ; this method 
also permits changing the spacing of the skids and stickers 
for dififerent kinds of lumber, and is especially recommended 
for red gum, black gum, and cotton gum (tupelo) for which 
it is best to have the stickers about 2 feet apart. 

For the beams and skids steel I-beams or inverted rail- 
road rails securely imbedded in the foundation are most per- 
man,ent. Creosoted timbers, or naturally durable woods, are 
also very satisfactory. If the wood is given no preservative 
treatment, its life will be increased somewhat by applying two 
coats of hot creosote at all points of contact. Untreated sap- 
wood so close to the ground will decay in a comparatively 
short time and may infect the lumber. 

Stickers — The stickers should be of heartwood, prefer- 
ably of some durable species, dressed on one side to uniform 
thickness and not over 4 inches wide. Narrower widths arc 



36 WOODEN BOX AND CRATE CONSTRUCTION 

recommended. It is very poor policy to use regular widths 
of lumber for cross pieces within the piles because little or 
no drying takes place where large areas are covered up, and 
decay may set in. The stickers should be % inch thick for 
inch lumber and up to 1>4 inches for thicker stock; they 
should be slightly longer than the width of the pile. 

The front and rear stickers should be flush with or pro- 
trude slightly beyond the front and rear of the lumber piles. 
The other stickers should be placed in alignment over the 
skids and parallel to the front of the lumber pile. 

Placing of Lumber — If possible, different lengths of lum- 
ber should be put in separate piles. No loose and unsup- 
ported ends should be permitted. A space of about 1 inch 
should be left between the edges of 1-inch boards in each 
course, and 2 inches between 2-inch boards. Lumber piled in 
the open should have each course project slightly over the 
course beneath on the front side of the pile so as to provide 
a forward pitch to the high end of the stack. For wide piles 
it is recommended that a vertical open space or flue be left 
in the middle of the pile, about the width of a board, extend- 
ing upward from the skid two-thirds the height of the pile. 

The top of the lumber pile should be closed with over- 
lapping boards laid so as to drain off all water. It is also 
desirable, especially for the better grades of lumber, to have 
this covering or roof project on all sides of the pile so as to 
keep out some of the snow and rain, and produce shade for 
the sides and ends. 

Size and Spacing of Piles — Lumber piles are usually 
built from 8 to 16 feet wide. The height depends on the 
character of the lumber, and the extent to which the yard is 
crowded. The space between piles should not be less than 
two feet ; four or five feet is better if yard conditions permit. 

Kiln-Drying Box Lumber^ — Lumber 1 inch thick requires 
from 2 months to a year for air-drying, but the green stock 
can, as a rule, be kiln-dried for box purposes in from 2 to 10 
days. Veneer or rotary-cut lumber i\ inch thick requires 
from 6 to 12 days for air-drying; the same material can be 
kiln-dried in about 12 hours. Kiln-drying at the saw mill 



^For information on the principles of kiln-drying and the operation of kilns see : 
Forestry Bulletin 104 — The Principles of Drying Lumber at Atmospheric Pressure, 
and Humidity Diagram, by H. D. Tiemann ; U. S. Department of Agriculture Bulletin 
552 — The Seasoning of Wood, by H. S. Betts ; and U. S. Department of Agriculture 
Bulletin 509 — The Theory of Drying and Its Application to the New Humidity Regu- 
lated and Recirculating Dry Kiln, by H. D. Tiemann ; The Kiln Drying of Lumber, 
by H. D. Tiemann, J. B. Lippincott & Co., Philadelphia, Pa. 



USE OF WOOD IN BOX AND CRATE CONSTRUCTON 37 

also prevents deterioration of the lumber, especially blue 
stain. 

The saving in time by kiln-drying greatly reduces the 
amount of stock it is necessary to carry in the yards. On the 
other hand, the cost of kiln equipment and the expense of 
kiln operation offset to some extent the advantages so gained. 

In deciding whether it pays to kiln-dry lumber instead of 
air-drying it, the following factors should be considered : 

Air-Drying Kiln-Drying 

Interest on capital invested in Interest on capital invested in 

ground occupied by lumber yard, ground occupied by kilns and track- 
yard equipment, and the large age, dry kilns, and equipment, in- 
amount of lumber kept in storage. eluding extra boiler capacity, stor- 

age sheds, and a small amount of 
Taxes on land and equipment. lumber kept in storage. 

Taxes on land, kilns, sheds, and 
Insurance on equipment and lum- equipment. 
her. Insurance on buildings, equipment 

and a comparatively small amount 
Depreciation of lumber and equip- of lumber. 
ment. Depreciation of buildings, equip- 

ment and lumber. 
Cost of handling lumber from the Cost of handling lumber from the 

time it is received until ready for time it is received until ready for 
shipment or manufacture. shipment or manufacture. 

Cost of operating of kilns : attend- 
ance, fuel, water, etc. 

THE USE OF VENEER IN THE CONSTRUCTION OF 
PACKING BOXES 

Definition — Veneer is a thin sheet of wood. There is no 
standard thickness above which it is called lumber. The 
common practice is to use the term veneer for all stock which 
has been cut on special veneer machinery, and lumber for that 
which is cut with ordinary circular or band saws. 

Although originally veneer was cut from high-priced cab- 
inet woods to save material, it is now cut extensively from 
common species, and is used for many purposes when light- 
ness rather than beauty is the principal requisite. It is well 
suited for the manufacture of small packages and even pack- 
ing boxes of considerable size because of its light weight and 
the small amount of wood required for construction of this 
kind. 

Manufacture of Veneer 

Method of Cutting — Most of the veneer used at present 
in box manufacture is resawed, rotary-cut, or sliced. The 
rotary and sliced methods reduce the waste and produce wide 



38 WOODEN BOX AND CRATE CONSTRUCTION 

stock. The veneer thus produced is comparatively free from 
defects, as only relatively smooth logs can be used for this 
purpose. Such material is cut with a special thin-edged 
veneer saw, a knife, or an ordinary band saw. 

Drying — Veneer, like other forms of lumber, should be 
properly dried in order to give satisfactory service. Drying 
is sometimes done in the open air in open sheds, the time 
required varying from several days to several weeks, depend- 
ing on the kind and thickness of the stock and weather con- 
ditions. This thin material may be dried in a kiln, in which 
case it must be weighted down to keep it straight. It is often 
put through progressive driers which dry the wood in from 
several minutes to an hour. These driers consist of long 
chambers with a series of belts or live rolls on which the 
veneer is carried through the apparatus. The temperature is 
comparatively high and the humidity low, so that rapid dry- 
ing results. There is little danger of casehardening very thin 
stock. Another type of drier consists of a series of heated 
iron plates between which the material is pressed. These 
plates separate at regular intervals so as to allow the mate- 
rial to shrink. 

Woods Used for Box Veneers 

Thin lumber is made from many kinds of woods, includ- 
ing most of our commercial species, but red gum leads all 
others in quantity used. Yellow pine and maple are also used 
largely in the manufacture of boxes, baskets, and crates. Cot- 
tonwood is a very desirable species for use in the production 
of veneer because it gives very little trouble in cutting. The 
sides and bottoms of cracker boxes and light Qgg cases are 
made principally of cottonwood stock. Elm is used largely 
for cheese boxes. Other species commonly used for thin 
stock in box and package manufacture are birch, beech, cot- 
ton gum (tupelo), basswood, sycamore, and Douglas fir; and 
many other commercial species are used to a smaller extent. 

Although very definite statistics are not available as to 
the amount of thin lumber used for boxes and fruit and vege- 
table packages, it is estimated that out of the total 6 bil- 
lion board feet of lumber annually used by the box industry, 
700 million feet log scale is used for thin stock. The use of 
thin lumber is gradually increasing. 

Most of the thin lumber or veneer used in boxes and 



USE OF WOOD IN BOX AND CRATE CONSTRUCTON 39 

crates is in single thicknesses securely fastened to relatively 
thick ends or cleats. 

Examples of the use of single-thickness stock for ship- 
ping containers are very common. The cheese box is one of 
the oldest forms. Vegetable barrels, baskets, berry boxes, 
fruit crates, cracker boxes, Qgg cases,, canned goods boxes, 
and many others, including a special type known as wire- 
bound boxes, are used extensively. 

Use of Plywood in Packing Boxes — The properties of 
veneer or thin lumber in single thicknesses are improved by 
gluing together three or more sheets with the grain crossing. 
The product is known as "plywood," and h-as the advantage 
of producing a comparatively strong and light piece of mate- 
rial in which the strength, stififnesi^ and shrinkage along and 
across the grain of the face pieces are more nearly equal than 
in lumber. Plywood also has greater resistance to splitting 
in nailing and to puncturing in handling. 

Plywood is not used very extensively in the manufacture 
of boxes, but it has distinct advantages over other forms of 
wood construction. A box properly made of plywood is ex- 
ceedingly strong for its weight. The principal objection to 
the more extended use of plywood in boxes is the cost in- 
volved in gluing up of the thin sheets. 

Plywood should be made up of an odd number of plies 
with the grain of successive plies at right angles to each other. 
The construction on the two sides of the core should be sym- 
metrical as to species, thickness of panels, and direction of 
grain. The strength in bending is less in the direction paral- 
lel to the grain of the face pieces, and greater at right angles 
to the grain of the face pieces than in boards of the same 
thickness and same kind of wood. A combination of faces of 
strong wood and a thick core of a light wood gives greater 
strength in bending than the same faces with a thinner core 
of the same weight of some heavier species. The glued sur- 
faces are not so likely to separate in plywood constructed 
with thin plies as in that made of thicker material. 

Plywood does not split in nailing so easily nor does it 
puncture so easily as a single board of the same thickness, the 
resistance increasing with the number of plies. The greater 
the number of plies, the straighter the plywood will remain 
with change in moisture content. Plywood in outdoor service 
will cup and twist least if it has a moisture content of from 
10 to 15 p.cr cent when it comes from the glue jiress. 



CHAPTER II 

BOX DESIGN 

Factors Influencing Details of Design — Characteristics of 
THE Various Styles of Boxes — Factors Determining the 
Amount of Strength Required — Factors Determining 
' the Size of a Box — Special Constructions. 

Box design may he defined as the development of definite 
details for constructing boxes which will deliver their con- 
tents to the purchaser in a satisfactory condition and at a 
minimum cost. The construction of more expensive boxes 
can not be justified unless they are to serve as an advertise- 
ing medium or perform some other service which warrants 
the additional cost. Among the factors which affect box 
economy is the cost of the following: raw materials, manu- 

Table 8. Thicknesses of Box Boards Obtained by Resawing or Dress- 
ing 4/4 TO 7/4-INCH Lumber^ 



Box boards, thickness 


Rough lumber, thickness^ 


Inches 


Inches 


3/16 rough or SIS 


3 pieces from 4/4 


1/4 rough or SIS 


3 pieces from 4/4 


5/16 rough or SIS 


3 pieces from 5/4 


3/8 rough or SIS 


2 pieces from 4/4 


7/16 rough or SIS 


2 pieces from 4/4 


1/2 rough or SIS 


2 pieces from 5/4 


9/16 rough or SIS 


2 pieces from 5/4 


5/8 rough or SIS 


2 pieces from 6/4 


11/16 rough 


2 pieces from 6/4 


11/16 SIS 


2 pieces from 7/4 


3/4 rough or SIS 


2 pieces from 7/4 


13/16 rough, SIS, or S2S 


1 piece from 4/4 


7/8 rough, SIS, or S2S 


1 piece from 4/4 


15/16 rough or SIS 


1 piece from 4/4 


4/4 rough 


1 piece from 4/4 


4/4 SIS 


1 piece from 5/4 



If box parts are to be dressed on two sides (S-2-S) and to be full thick- 
ness also, use next thickness of lumber except where specified in above table. 



'Adopted by the National Association of Box Manufacturers — August 5, 1915. 
^If full thickness without variation is required, then use the next greater 
thickness. 



40 



BOX DESIGN 



41 



facturing (including assembling), handling, storage, freight, 
and losses due to box failures. A designer of boxes should 
endeavor to gain a knowledge of all these phases of the 
problem. 

FACTORS INFLUENCING DETAILS OF DESIGN 

Lumber and Veneer 

Availability and Supply — Lumber of suitable thickness 
for box construction is usually obtained by resawing regular 
sizes of low grade stock, although in some sections the logs 
are sawed directly into lumber of the desired thicknesses. 

The designer should have definite information regarding 
the properties, grades, widths, thicknesses, lengths, supply, 
and cost of lumber of the species available where the box is 
to be manufactured and the commodity for which the box is 
made, and the manner in which the commodity is to be 
packed. Data showing what thicknesses can be obtained 
from commercial lumber by resawing and surfacing should 
be at hand. (See Tables 8 and 9.) The dimensions of mate- 

Table 9. Standard Thicknesses of Hardwoods 

Adopted by the National Hardwood Lumber Association and the Amer- 
ican Hardwood Manufacturers' Association.^ 



Rough thickness 


Surfaced thickness 


Inches 




Inches 


3/8 S-2-S to 




3/16 


1/2 S-2-S to 




5/16 


5/8 S-2-S to 




7/16 


3/4 S-2-S to 




9/16 


1 S-2-S to 




13/16 


1 1/4 S-2-S to 


1 


3/32 


1 1/2 S-2-S to 


1 


11/32 


1 3/4 S-2-S to 


1 


1/2 


2 S-2-S to 


1 


3/4 


2 1/2 S-2-S to 


2 


1/4 


3 S-2-S to 


2 


3/4 


3 1/2 S-2-S to 


3 


1/4 


4 S-2-S to 


3 


3/4 



Lumber surfaced on one side only must be 1/16 inch full of the above 
thickness. 

rial in boxes made of sawed lumber must, if not inconsistent 
with other requirements, be such as will use the material with 
the least waste in resawing, surfacing and cutting to size. 



^Formerly tho Hardwood Manufacturers' Association. 



42 WOODEN BOX AND CRATE CONSTRUCTION 

The main waste is due to trimming to required length and 
width and at the same time eliminating checked ends, splits, 
loose and rotten knots, and knot holes. Rotary-cut veneer 
can be obtained in lengths up to 60 inches and in any width 
that can be readily handled. 

Cost — The actual cost of lumber is not the purchase price, 
but the cost of the usable material after due credit has been 
allowed for salvage of waste. Obviously it is important that 
the amount of waste which occurs in the various grades of 
material be accurately known to the designer. 

Manufacturing Limitations 

Equipment — Design will necessarily be influenced by the 
box-making equipment available. Equipment for making the 
common types of boxes is more or less standardized. Ac- 
curate information on the kind and cost of each operation 
performed and the quantity of work produced by each ma- 
chine is therefore requisite to the design of such a box as will 
cost the least to manufacture. 

Details which require the installing of special machinery 
for their execution should be avoided if possible, unless they 
are improvements of such a character that there will be a 
continued demand for their application. The experience of 
the Forest Products Laboratory, however, is that in a large 
majority of cases the common designs of boxes are the more 
efficient and that the special features in other designs usually 
interfere with balanced construction. 

Cost of Operation — The cost of various machine oper- 
ations depends on numerous factors such as general factory 
overhead charges, depreciation on machines, power charges, 
cost of tools, operator's wages, and volume of work done. 
The standardization of box and crate design has proved one 
of the chief factors in the reduction of cost of manufacture. 
Unusual styles or special features always increase the cost 
and as a rule decrease the serviceability of shipping containers. 

Styles of Boxes — There are a number of styles of nailed 
wooden boxes so universally iised that they may be called 
standard nailed boxes. (See Plate IIL) 

Many special styles of boxes have been developed for 
particular conditions and commodities. Whether or not a 
box which can be returned and refilled should be adopted for 
carrying a commodity depends wholly upon the economic 



BOX DESIGN 43 

phases of the problem. If box materials continue to increase 
in cost, the use of returnable boxes will no doubt increase. 
Returnable boxes should, so far as possible, be made collaps- 
ible, as they will then occupy less space in shipment and 
storage when empty. 

Under some conditions boxes which can be easily and 
quickly opened are demanded. This requirement has been 
especially urgent in many of the United States Army Ord- 
nance boxes. Types of such easily-opened boxes are shown 
in Plate IV. 

Balanced Construction and Factors Affecting Strength^ 

When all elements in the construction of a box resist 
equally the destructive hazards of service, it is balanced in 
construction. A box may be balanced in construction and yet 
be excessively heavy, too strong, and uneconomical in the use 
of material ; or it may be too light and weak for service. With 
unbalanced boxes which render satisfactory service there is 
frequently a waste of material in the stronger parts ; and an 
equally or even more serviceable box may be obtained by 
reducing the strength of the stronger parts until they are in 
balance with the weaker parts. This is because the parts 
which are excessively heavy transmit an undue amount of the 
shocks and stresses to the lighter parts, thus causing the 
lighter parts to fail sooner. With a balanced box there is a 
more even distribution and absorption of stresses and shocks. 
Excessive thickness of lumber in sides, top, or bottom of a 
box will also produce undue stresses in the nails and, under 
certain conditions, will be a source of weakness. 

The chief problem in box design is to detail the parts so 
that balanced construction and proper strength are both 
obtained, and at minimum cost. Balanced construction and 
a proper degree of strength can be determined by suitable 
methods of testing." 

Width of Stock and Joints — Stock which is wide enough 
to make one-piece box parts has various advantages in com- 
parison with narrower stock. Joints which would otherwise 
occur are avoided, thus increasing the rigidity of the boxes 
and their resistance to "weaving action." In boxes of Style 1, 



^For strength data on various types of boxes, see Forest Service Circular No. 
214, obtainable from the Superintendent of Documents, Washington, D. C, at five 
cents a copy. 

^See chapter IV, page 87. 



44 WOODEN BOX AND CRATE CONSTRUCTION 

Plate III, having no cleats but single-piece ends or two-piece 
with, corrugated fasteners, it is very desirable to have one- 
piece sides because they diminish the liability to failure and 
make a more dependable construction. A tighter box is in- 
sured with single-piece parts. Larger knots can be permitted 
in boxes with single piece parts because the allowable sizes of 
knots bear a direct ratio to the width of the board. Single- 
piece parts reduce machine and labor costs ; but if required 
exclusively, they would greatly increase material costs. 

When two or more pieces are used in any part, the abut- 
ting edges are usually tightly joined. This may be accom- 
plished in several ways; the simplest form of joint between 
the edges of two boards is shown in figure 1, Plate XV. The 
abutting edges of the pieces should be straight and square 
with their faces, and in contact throughout so as to make a 
tight joint. 

When some other than the butt joint is used for joining 
edges of boards, it is called a matched joint. One type of 
matching which is used to a limited extent in box construc- 
tion when the lumber is ^ inch or more in thickness 
is shown by figure 6, Plate XV. Such lumber, known 
as shiplap, milled to join in this way, can be obtained in vari- 
ous widths, and this is undoubtedly the reason why it some- 
times appears in box construction. It is not as effective for 
tight construction as other matched joints since the adjacent 
boards can bend independently. 

The matched joint illustrated by figure 5, Plate XV, is 
very commonly used for joining box boards. In addition to 
matching, the pieces may be glued or fastened together with 
corrugated fasteners. This construction makes it possible, 
when the material is over ^ inch thick, for the weaker boards 
and the boards which receive the more severe thrusts in 
service to be supported to some extent along their edges by 
the adjoining boards. 

An excellent matched joint (Linderman) for box work is 
shown in figure 3, Plate XV. The taper lengthwise in this 
joint produces a wedging action between the parts and binds 
the two pieces tightly together when they are forced into 
proper position. As the two pieces are forced together, glue 
is applied to the uniting surfaces, which, if the gluing is 
properly done, increases the strength of the joint and enables 
the combined parts to approximate a single piece in char- 



BOX DESIGN 45 

acter; it is less effective in material ^ inch or less in thick- 
ness. 

In constructing boxes such as Styles 1 and 6, Plate III, 
and those in figures 1 and 2, Plate IV, joints in the sides and 
ends should be so located that there is considerable distance 
between their respective planes, to avoid a line of weakness 
around the box. 

An important advantage of all matched joints is that a 
tight box is maintained even though some shrinkage occurs. 

Corrugated Fasteners — In figure 2, Plate XV, several 
types of fasteners are shown. The fasteners with parallel cor- 
rugations may also be obtained in continuous coils (figure 4 
Plate XV) for use on automatic driving machines which cut 
and drive the fasteners in one operation. 

These fasteners may be used for holding pieces together 
and preventing relative endwise movement in the joints 
(figures 1, 5, and 6, Plate XV) and for preventing relative end- 
wise movement of pieces in Linderman joints when poorly 
glued (figure 3, Plate XV). They are also driven across splits 
and large checks to prevent further development of such 
defects ; greater efficiency is obtained in such cases if the 
fasteners are driven from both sides. 

The depth of the fasteners should be slightly less than 
the thickness of the pieces into which they are driven so that 
the cutting edge may not protrude after driving. The fasten- 
ers with divergent corrugations have a tendency to draw the 
pieces closer together when they are driven. 

Physical Properties of Wood — The physical properties of 
wood have a vital influence on the strength of a box. The 
effect of using material the density of which is much lower 
than the average for the species is to produce a box in which 
the low density parts of it are weak and will usually break 
quickly in service. 

Material of low bending resistance is not suitable for long 
boxes in which the contents are of such a nature that con- 
siderable stiffness in the material is required to maintain the 
shape of the box. 

Increased resistance to splitting^ is desirable, especially 
for ends which are not cleated or otherwise reinforced. If 
some method of reinforcing against splitting must be used, 
the cost of the box is increased unless the extra charges are 



^See also nailing qualities of wood, page 51 



46 



WOODEN BOX AND CRATE CONSTRUCTION 



balanced by a reduction in the thickness of material made 
possible by such reinforcement. 

Failures by puncturing are infrequent. Inspectors at the 
ports of embarkation during war shipments estimated that less 
than one per cent of boxes inspected showed damage due to 
puncturing. The damage due to this cause when thin mate- 



Nailed and tested at once at 15% moisture. 



100% 



90% 



Nailed and tested at once at 30% moisture. 



75% 



Nailed at 15%, tested at 5% moisture, 4 months storage. 



50% 



Nailed and tested at once at 5% moisture. 



15% 
Nailed at 30%, tested at 5% moisture. One year in storage. 

■I^H 10% 

Nailed at 5%, tested at 35% moisture. Stored 2 weeks in exhaust 
steam. 

^ 10% 

Nailed at 5%, dried to 4^%, tested at 35% moisture. Two weeks drj 
storage, 2 weeks in steam. 

mi^m 10% 

Nailed at 5%, steamed to 35%, tested at 4V2% moisture. Two weekr 
in steam, 2 weeks dry storage. 

Most perfect boxes nailed from shooks at 15% moisture. 
Boxes nailed at 15% and tested at once, taken as a base. 



Fig. 12 — Effect of condition and change of condition of lumber on strength 

of boxes in storage. Boxes for 2 doz. No. 3 cans, nailed with 

seven cement-coated nails to each nailing edge. Chart based 

on tests to date. Data insufficient for accurate 

comparisons. 



rial must be used can be reduced by substituting plywood for 
veneer, since it offers more resistance to puncturing. If 
warped lumber or veneer is used, initial stresses are produced 



BOX DESIGN 



47 



when such material is forced to a-ssume the proper shape in 
assembling the box. Such initial stresses decrease the amount 
of strength remaining for resisting the hazards of service. 
Boxes made of such material may also be somewhat mis- 
shapen. 

Moisture Content^ — The moisture content of the material 
used in constructing boxes influences their strength greatly, 
and in various ways. An abnormal amount of moisture in 
box material causes the points of the nails to pull more easily 
from the wood, the heads to pull through the wood, and the 
shanks of the nails to shear out at the ends of the boards. 
When boxes made of green or wet material subsequently dry 
out, the nails become loose and pull easily. The boards also 
split and check because the nails resist the shrinkage, which 
is the normal result of drying. Variations and changes in the 




Fig. 13 — Effect of shrinkage on strapped boxes. Boxes made and strapped 

at a 30 per cent moisture content ; the boxes were photographed 

after drying out to 10 per cent moisture Content. 

amounts of moisture contained in box lumber affect the 
strength of a box, as indicated by the results of tests given 
in figure 12. 

The moisture content of box material has a very great 
influence on the maintenance of the strengthening effect of 
strapping and wire bands. If shrinkage occurs after strapping 
is nailed on, the strapping buckles between the nails. (See 
figure 13.) Straps with ends joined by some sealing or 



'See page 15 for general discussion of moisture content. 



48 



WOODEN BOX AND CRATE CONSTRUCTION 



clamping device often become so loose through shrinkage of 
the wood that unless nailed in place they will easily slip ofif 
the box. Inspectors have reported that large quantities of 
straps which have slipped off boxes, with the seals unbroken, 
are at times left in freight cars after unloading. A similar 
loosening effect may occur when boxes are stored for a con- 
siderable time. The effect of shrinkage on the usefulness of 
wire bands is similar to that on strapping. 

It is apparent that when straps or wire ties are to be 
used, the box material should have such a percentage of 
moisture as it is likely to retain after construction and pack- 
ing is completed ; this is usually between 12 and 18 per cent. 
Strapping should, if possible, be put on boxes under maximum 
tension immediately prior to shipment, as the bad buckling 
and loosening effects from shrinkage in storage are not then 
so apt to occur. 





a 

< 




« 


H L 


.-. 


Q 

< 


J 




' 




VOL. 3 


t At 1 


VOL. 2 


1 


VOL. 3 


l' >• 


VOL. 3 




i 4l j 


VOL. 1 


1 


it 
I 


1, 


L = 1S FT. 
H L 


1 
—J 





? 




= 1 






=> 



Fig. U 



-Division of a beam into volumes for describing the location of 
knots. 



Defects^ — Boxes are ordinarily made of low-grade lum- 
ber containing various defects. Such defects as do not affect 
the serviceability of the box should be allowed to remain, in 
order that the amount of waste, and consequently the actual 
cost of material, may be the minimum. 

Larger knots may be permitted in wide pieces than in 
narrow widths, but knots should not be permitted to interfere 
with proper nailing. A knot hole, besides being weakening, 
may cause loss of the contents of a box. Knots are most 
weakening in that part of a beam indicated by volume 1 in 
figure 14, next if located in volume 2, and least weakening if 
on any part of volume 3. Figure 15 shows a crate slat which 
failed on account of too large a knot at A. 

Knots should be limited as to size, because the weakening 
effect is practically proportional to their effective diameter, 
measured as shown in Plate I. A satisfactory method of lim- 



^See pages 8 to 10 for description of various defects. 



i 



BOX DESIGN 



49 




50 



WOODEN BOX AND CRATE CONSTRUCTION 



iting the size is to require that the effective diameter shall not 
exceed a certain fraction of the width of the board. 

Shakes and checks are objectionable in material for boxes 
for certain commodities. They may develop into splits and 

Table 10. Holding Power of Nails in Side and End Grain of 
Various Species 

7d Cement-coated nails driven to a depth of one inch and pulled 

immediately 



Species 



Per cent of 
moisture 



Group P 

Pine, white 

Pine, Norway 

Pine, jack 

Aspen 

Spruce, red 

Spruce, white 

Pine, Western yellow 

Cottonwood 

Basswood 

Fir, white 

Cedar 



Group II 

Hemlock 

Pine, Southern loblolly yellow 
Longleaf 



Group III 

Elm, white 

Gum, heartwood 
Gum, sapwood . . 

Sycamore 

Maple, silver . . . 



Group IV 

Maple.. _ 

Ash, white . . . 

Beech 

Oak, cow 

Oak, post 

Oak, red 

Oak, white . . . 
Birch 



7.7 
7.4 
7.6 
6.5 
10.7 
7.6 
7.2 
6.8 
6.5 
7.6 
9.3 



8.6 

7.7 
8.2 



8.2 
6.0 
8.1 
7.0 
6.8 



9.3 
8.9 
8.4 
4.3 
7.3 
7.6 
7.3 
8.6 



specific 
gravity 



.391 
.507 
.429 
.412 
.413 
.396 
.433 
.343 
.412 
.437 
.315 



.501 
.516 
.599 



.537 
.488 
.433 
.552 
.506 



.643 
.640 
.669 
.756 
.732 
.660 
.696 
.661 



Withdrawing pull 
in lbs. 



End grain Side grain 



122 
149 
145 
141 
133 
131 

96 
129 
124 
101 

93 



139 
142 
196 



212 
179 
189 
243 
252 



350 
347 
322 

277 
351 
297 
268 
298 



203 
254 
245 
186 
199 
196 
196 
177 
175 
183 
144 



236 
268 
313 



305 
243 
220 
314 
304 



406 
407 
414 
323 
345 
333 
289 
406 



cracks and thus increase the liability of the box to fail in 
service. A board containing large checks or shakes which 
extend through from one face to the other should be consid- 
ered as two boards. One method of preventing splits, checks, 
or shakes from increasing in size is to drive corrugated fas- 



^Data are not available on all woods in each group. 



BOX DESIGN 51 

teners across the apparent line of development. These corru- 
gated fasteners should be driven only when the board can be 
firmly supported opposite the point of driving, as otherwise 
the attempted remedy may prove to be detrimental. 

Cross grain, a slope of the fibers with respect to the main 
axis of a stick, is one of the most serious defects afifecting the 
strength. of box and crate material because it is very common 
and not easily detected. 

Cross grain in box lumber is detrimental because it in- 
creases the danger of failure in boards which are subjected to 
bending and puncturing stresses ; also because it makes the 
wood more susceptible to splitting when nails are driven where 
the defect occurs. 

Insect holes, if large and present in sufficient numbers, 
frequently impair the strength of box lumber. They also 
alTect the appearance and tightness of boxes, but in some 
cases such material can be used with a resulting saving in cost. 

Rot is often found in low grades of lumber; the extent to 
which it may be permitted in box and crate material depends 
on the purpose for which the container is intended. Rot 
should not be allowed in pieces subjected to great stresses, 
or wherever nails are driven. The slat C at the bottom of 
the crate in figure 15 broke because it was partly decayed. 

Occasional worm holes in wood do not seriously weaken 
it, but pieces which are badly perforated should not be used 
where strength or nail-holding power is essential. As a rule, 
worm holes indicate decay in the material in which they 
occur. 

Nailing Qualities of Wood — The nailing qualities of the 
wood are of vital importance in box construction. It is waste- 
ful practice to make a nailed box of lumber of considerable 
strength unless the parts are nailed together in such a way 
as to balance the construction. 

The serviceability^ of a nailed joint varies with the, dens- 
ity of the wood, the ease with which it is split and sheared 
by nails, the initial moisture content, changes in moisture 
content^, the character and location of defects, and the direc- 
tion of the nails relative to the grain of the wood. 

It will be observed from the preceding table that, in gen- 
eral, the difiference between the resistances of the nails to 



^See page 53 for the effect of nails on the strength of a joint. 
-See page 15, moisture content. 



52 WOODEN BOX AND CRATE CONSTRUCTION 

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BOX DESIGN S3 

pulling- from the end grain and from the side grain is greater 
for the light soft wood than for the heavier dense ones. 

At times it is necessary to use denser woods for the cleats 
or ends or both than are used for the other parts of the box 
in order to secure sufficient nail-holding power to balance the 
construction. 

Some woods are very susceptible to nail splitting ; also 
nails easily shear out at the ends of the boards of some spe- 
cies. Both of these difficulties increase the probability of the 
ends being pulled away from sides, top, and bottom of the 
box. Nails driven in checks, rot, etc., have little holding 
power. The holding power of nails changes with the lapse 
of time after driving, as shown in figure 16. 

Tests on the holding power of nails driven parallel with 
and at an angle to the grain, as. shown in figure 3, Plate 
VII, show no appreciable difiference in holding power when 
pulled immediately. In these tests the direction of pull was 
perpendicular to the surface of the board. Nails were sim- 
ilarly driven in green pine, which was then dried thoroughly 
in an oven at a temperature of 100° C, before testing; and it 
was found that while the diagonally-nailed pieces started to 
fail at lower loads than the straight nailed, the diagonally- 
nailed pieces soon developed more strength with the result 
that the force required to withdraw the nails was considerably 
higher than for those with straight nailing. These tests in- 
dicate that diagonal nailing may be of some advantage if 
boxes are to remain in storage where the moisture content 
will be reduced. 

Fastenings and Reinforcements — Nails are the most com- 
mon fastenings for box materials. The serviceability of a 
nailed joint varies with dififerent nail characteristics and de- 
tails of nailing, such as the character of the shank surface, the 
length and diameter of the shank, the flexibility of the shank, 
the size of the head, and the number or spacing of the nails. 
A special type of nails known as box nails^ is made for use 
in the box industry. In order to minimize the splitting of 
material these nails are made of smaller wire than the ordinary 
plain wire nails used in building construction, though they 
must be of sufficient diameter not to bend or kink in driving. 
Another advantage of slender nails is that they are not so 
readily loosened in the wood as those of larger diameter and 
equal length, because the slender nails bend more readily un- 



^See pages 139-140 for table of sizes of nails, etc. 



54 



WOODEN BOX AND CRATE CONSTRUCTION 




Cornor of £nd Corner o^ S'Ob 

NAIL/NG 0£TA/LS fO/^ STYLE -/- BOXES 




Corner of End 



Corner of S'lfe 



NA/UNO DETAILS EOf? STYLE- Z- BOXES 




Oorner c 
NX)/LV/VG 




DET-4/LS rOf^ 



Corner of End """ Corner of Side 

NAILING DETAILS EOR STYLE-J-BOXES 




Corr>er of £r>d 



C ornmr of Side 



NOTES 

For all styles when the end and cleats are 
% inch or less, d r= % inch. For all thicker 
stock, d := % inch. 

WTien w r= 2 inches or less, r := % inch. 
For larger values of w, r ^ % inch. 

In style-1, L zi: length of nails holding sides. 

In style-2%, n = % to % of an inch. 

Nails thru cleats and ends should be long 
enough to clinch well, and spaced approxi- 
mately the same as in the adjacent side, top 
or bottom as shov\ii. 

Good construction is obtained with 6d nails 
by maldng s :;: 1% inches for sides and s ^ 2 
inches for tops and bottoms. With larger nails 
s may be increased % inch for each penny in 
excess of six. These values of s may be varied 
enough to allow an odd number of nails to be 
used in edges where the nails are staggered in 
two rows, also to prevent nails being driven in 
eracks. and to give additional nails when con- 
ditions demand. Bverj' board shall have at 
least two nails in each nailing edge. 



NAILING DSTA/LS rOP STYLEdBOXES 



Fig. 17 — Details for nailing standard styles of boxes for domestic shipment. 



BOX DESIGN 55 

der the shocks of rough haridhng and the weaving strains that 
a box receives in transportation and are not worked back 
and forth their full length. If nails are too slim, however, the 
excessive bending, which readily occurs, will frequently cause 
them to break between the parts which they unite. Box 
nails may be obtained cement-coated, or with plain or barbed 
shanks. The cement coating increases the friction between 
the shank of the nail and the wood. Barbed nails are so 
called because the shanks of the nails have on their surfaces 
a series of small barbs or teeth. 

The holding power of nails of the same kind but of dif- 
ferent sizes against withdrawal in line with the shank is for 
ordinary sizes approximately proportional to the amount of 
shank surface in contact with the wood. If more holding 
power is needed, it is preferable to increase the number or 
length of the nails rather than their diameter. In this way 
the advantages of slim nails are retained, and the additional 
shank surface is secured with less additional metal in the nails. 

The size and spacing of nails should be such as will not 
cause an unreasonable number of failures because of splitting 
the material in driving. 

One of the difficult problems in a nailed box is to secure 
sufficient nail-holding power to stress all the wooden parts of 
a box to their maximum, and still maintain balanced construc- 
tion. In some species of wood a large number of small nails 
may be recjuired, and in others a smaller number of larger 
nails may be necessary to secure the desired results. Box 
woods are divided into four groups according to their nailing 
qualities.^. The nailing schedule on page 102 gives informa- 
tion for proper nailing of boxes constructed of woods from 
these groups. 

Directions for Nailing — General directions and details 
for nailing cleats, sides, top, and bottom to ends of several 
styles of boxes for domestic shipment are given on page 103. 
(See also figure 17.) For foreign shipment the spacing should 
be about one-half inch less than given on page 102. 

In figure 18 are shown the relative amounts of rough 
handling required to cause loss of contents in boxes con- 
structed with various spacing of nails. A box with seven 
nails per nailing edge is taken as the basis for comparison. 

The size and spacing of nails in some instances depends 
largely on the properties of the material upon which the heads 

iSee page 100 for grouping of species. 



56 WOODEN BOX AND CRATE CONSTRUCTION 

of the nails rest. If this material is of low density and easily 
sheared by the nails, it is advisable to have them closer to- 





8 


nails per 


nailing edge. 








100% 
taken as 


a base. 


7 


nails per 


nailing edge. 




75% 
nailing 


edge 


6 


nails per 


nailing edge. 

22% 

nailing edge. . 
: with seven nail 


5 per 


d^^l 


^^^^^H 


5 


nails per 
A bo> 



Fig. 18 — Relation of number of nails to amount of rough handling required 
to cause loss of contents. Nailed boxes for 2 doz. No. 3 cans. 

gether than v^ould be required with a denser wood offering 
more resistance to such shearing action. 

Placing nails closer together gives more holding power 
per inch of nailing edge for the wood in which the points are 
held, unless the nails become so close that their holding power 
is reduced by the splitting of the wood. 

Side Nailing- — The term "side nailing" refers to the nail- 
ing of the top and bottom to the edges of the sides. If the 
boards are less than ^jr inch in thickness, such nailing will 
add little to the serviceability^ of the box but will make a 
tighter box, provided th.e strains due to the contents and the 
hazards encountered are not severe enough to spring the 
boards and produce nail splitting at these edges. The size 
of nails should be as shown by the nailing schedule on page 
102. Six penny nails and smaller should be spaced approxi- 
mately six inches apart, and this distance increased one inch 
for each penny over six. 

Nails for Clinching — The character of the surface of the 
shank is relatively unimportant in nails to be clinched, 
the head and the clinched end being the important factors. 
Slender nails are to be preferred because they lessen the dan- 
ger of splitting the wood and clinch more easily. The use of 
cleating nails made with a "side point" is increasing. The 
long slender point turns back into the wood when driven and 
g^ives more uniform results than right-angled clinching. 



^See discussion of strapping, page 60. 



BOX DESIGN 



57 



Large Nail Heads^ — Tests have demonstrated that large 
nail heads have considerable advantage over small ones bc- 




FiG. 19 — Injury to wood fiber resulting from overdriving nails. 

cause of the additional resistance offered to being pulled di- 
rectly through the wood. Large heads also prevent the shanks 
of the nails from shearing out as easily at the ends of the 



Table 11. Effect of Size of Heads on Strength of a Nailed Joint 











•=• 






Shear 






Size of 


Diameter 


Load 


Heads 


Nails 


Load 


Heads 


Nails 


Material 


nail 


of heads 


per nail 


off 


broken 


per nail 


off 


broken 






inches 


pounds 


% total 


% total 


pounds 


To total 


% total 




6d 


.36 


312 








186 










6d 


.26 


257 








155 










6d 


.24 


250 








154 








5/16-inch red gum 


5d 


.28 


213 


100 





158 


33 


16 


rotary cut 


5d 


.22 


196 


22 





152 


8 


8 




5d 


.19 


212 








164 










4d 


.28 


239 


83 





173 


67 


16 




4d 


.22 


248 


100 





168 


33 







4d 


.19 


222 








163 










6d 


.36 


220 


11 





164 










6d 


.26 


194 








139 










6d 


.24 


181 








139 








3/8-inch sawed 


5d 


.28 


178 


33 





138 


33 


17 


white pine 


5d 


.22 


149 








142 


8 


8 




5d 


.19 


122 








134 










4d 


.28 


154 


22 





172 


33 


67 




4d 


.22 


146 








161 


11 


22 




4d 


.19 


116 








150 









boards when thin material is used.' In many nails with extra 
large heads the material where the shank joins the head is so 
thin that failures frequently occur in the nail at this point, 
thus preventing to a large extent any addition to the strength 
of the box. Large headed nails are advantageous for mate- 



^See page 139 Appendix for table of size and thickness of heads. 



58 



WOODEN BOX AND CRATE CONSTRUCTION 



rial which contains many checks or which splits easily and 
for thin and low-density material ; in fact, when thin material 
is being nailed the size of the head and the length of the nail 
are of nearly equal importance, with the necessity for large 



c 


\ 


















0) 


200 


















^ < 

3 


-H 


V 
















\- 
T3 

ns 

lU 

I 

'S 

Z 




N 
















100 




\ 














3 

D. 
o 








\ 


\ 










•a 

Hi 

t. 

3 








\ 


k > 










DC 

(A 

■a 

c 

3 










\ 










D. 




Thic 


mess of 
3 


<^iHr» 














1 


2 


4 


5 



Amount overdriven in one-s,ixteenth-incli units 

Fig. 20. — Efifect of overdriving nails 

heads increasing as the thickness of the material is reduced. 

In Table 11 are shown results on approximately 100 nails 
with various sizes of heads. The small heads are the stand- 
ard sizes for the different nails. It is shown that a very large 
percentage of the heads pulled from the four or five penny 
nails. 

Overdriving Nails — One of the serious faults in nailing 
boxes is overdriving. Nails should be driven until the top of 
the head is just flush with the surface of the material. Over- 
driving crushes and injures the wood fibers (figure 19) and 
decreases the strength to an extent which depends on the 



BOX DESIGN 



59 



amount of overdriving (figure 20). On the other hand, if the 
heads of the nails are not driven flush with the surface, the 
joint between the boards is not so tight and rigid as it would 
be otherwise, also there is danger of the nail heads catching 
on objects, especially strapping on other boxes. 

Screws — Screws are an admirable fastening when properly 
driven. They permit a box to be easily opened without dan- 
ger of injury to box or contents fr(jm bars, chisels, or other 
tools. Boxes made with screws are also easily closed again 
for reshipping, which feature may be objectionable with ref- 
erence to theft of goods in transit. Some method of sealing 
boxes which are closed with screws may be used to lessen the 
thieving losses. Other objections to screws are their cost, 
the cost of proper driving, and the great tendency to drive 
screws improperly their full length with a hammer, thereby 
sacrificing much of the strength that they should give. 

The data^ in Table 12 show the efifect of different methods 
of driving on the holding power of No. 12 screws. 

Table 12. Resistance to Withdrawal of No. 12 Screws 

Screws 1-34 inches long, driven to one inch depth in holes Yg inch in 
diameter. 







Method c 


f driving 




Kind of wood 


Screw 


driver 


Ham 


mer2 




Pounds 


Per cent 


Pounds 


Per cent 


Basswood 


478 

1144 

687 
841 


OOOO 

oooo 


281 
681 
403 
570 


59 


Yellow pine 


60 


Red gum 


59 


Birch 


68 



Staples — Staples are used for fastening both wire bands'* 
and flat metal straps in place. To secure good holding power 
they should be driven for a considerable distance into solid 
wood and if driven into thin material the points should be 
clinched. 

In holding box-strapping in place, staples have an ad- 
vantage because they do not weaken it by puncturing as nails 
do, and they also hold the edges of a strap down together and 
present a curved part to strike against the edges of straps on 
another box, thus lessening the danger of catching and tear- 
ing them ofif. 

^See page 63 for information on cleats fastened with nails, wood screws, and 
drive screws. 

'One final turn with screw driver. 
■ 'See discussion of wirebound boxes on page 67. 



60 WOODEN BOX AND CRATE CONSTRUCTION 

Staples will not, as nails do, hold the tension in strap- 
ping, and therefore some method must be used of accomplish- 
ing this by sealing or fastening the ends together. 

Strapping and Wire Bindings — The use of metal bindings 
around boxes may serve one or more of the following pur- 
poses : 

1. To reinforce the package and increase its service- 
ability. 

2. To minimize pilfering. 

3. To secure lighter, yet equally serviceable packages 
Types of Metal Bindings 

' , f Annealed 

l^lat straps. . 



Metal bindings. 



Unannealed 

Wires J Single wire 

Two or more wires twisted 

Two types of metal binding are in common use, viz. : 
fiat straps and wires. 

Flat straps are either annealed or unannealed. The dif- 
ferences in the properties of these two kinds of metal strap- 
ping result from a special heat treatment given unannealed 
strapping, thus producing annealed strapping. 

Annealed strapping, as a result of this treatment, has a 
much lower tensile strength, stretches considerably more be- 
fore failure or under a given load than unannealed strapping 
of the same size and is also more easily penetrated by nails. 
There are many special types of annealed strapping such as 
the plain, embossed, and corrugated, as well as various other 
types, that have holes or slots cut to receive the nails. 

Wire ordinarily used for box construction is annealed. 
It is used either as a single strand, ordinarily held in place 
by twisting the ends, or in two or more strands twisted to- 
gether and held in place by nails driven through spaces be- 
tween the wires. 

Plain unannealed strapping is generally applied by fas- 
tening the overlapping ends with a seal. The seal should 
provide a joint whose strength is nearly equal to that of the 
strap. 

Straps nailed around the extreme ends act somewhat as 
a cleat in resisting skewing or weaving of the box; retard the 
nails pulling from the ends ; prevent the nails in the straps 
from pulling the heads through the sides, top, and bottom ; 
and assist in preventing the nails from shearing out at the 
ends of the boards by acting in the nature of washers under 
the nail heads. This method of reinforcement also gives more 



BOX DESIGN 61 

secure nailing because the nails driven through the straps are 
in addition to those ordinarily used in the manufacture of the 
box. The strapping should be held in place with nails of the 
same size as those used to hold the sides, top, and bottom to 
the ends. 

Nailless straps placed some distance from the ends of a 
box absorb considerable shock which is ordinarily trans- 
mitted to the sides, top, and bottom, and thus relieve the 
direct pull on the nails in the end and also reduce failures due 
to the sides, top, and bottom splitting or breaking across the 
grain. Nailless straps do not add as much rigidity to a box 
as nailed straps and have less value in reducing shear on the 
nails in the ends of the sides, top, and bottom. In some cases 
nailless straps permit the use of thinner material in the sides, 
top, and bottom than is permitted by straps nailed around the 
end of the box. 

Either annealed or unannealed strapping may be used 
when nailed around the box, whereas, only unannealed strap- 
ping should be used when held in place with a seal. 

Metal bindings, particularly the nailless variety, to be 
most effective, should be drawn sufficiently tight to cut into 
the corners of the box, and maintained under considerable 
tension until the box has served the desired purpose. 

One method of retaining the tension in nailless strapping 
is by building the box in such a manner that neither the top 
nor bottom laps the sides. The tension of the strapping 
when drawn snug is sufficient to spring the sides, top and 
bottom of the box in against the contents so that the edge 
boards overlap near the center. As a result the middle of the 
box is smaller than the ends, and the straps will not slip off, 
even though the box shrinks. 

Another method of applying straps between the ends is 
to put battens^ on each face as shown in figure 1, Plate V, 
and then nail the straps to the battens. The battens make it 
possible to use longer nails without injuring the contents. In 
some instances, the straps may, in the absence of such bat- 
tens, be nailed directly to faces of the box, if the material 
packed will not be injured by the nail points. 

Shipping containers are frequently subjected to adverse 
moisture conditions and for that reason the metal bindings 
should be treated to resist rust. 

Boxes having comparatively thin sides, top, and bottom 



'See page 62 foi' discussion of battens. 



62 WOODEN BOX AND CRATE CONSTRUCTION 

and bound with metal bindings often are more serviceable 
than those constructed of heavier lumber without such bind- 
ings. In some cases it is possible to reduce the thicknesses 
of material 20 per cent or more and at the same time pernrit 
the use of a poorer grade of lumber when metal bindings are 
properly used, without any reduction in serviceability of the 
container. 

Reinforcements and Handles 

Corner Irons, Hinges, and Locks — Corner irons may be 
necessary on boxes for certain conditions of service, such as 
returnable boxes and heavy chests. The style of iron to be 
used will depend entirely on the conditions of service. 

The important requirements of hinges and locks are that 
they hold the cover securely in place, do not project so as to 
interfere with handling and stacking, and do not easily get 
out of usable condition. Locks ordinarily should be of such 
design that they may be held in a closed position by a seal 
rather than a key. Hinges should allow the cover to open 
until the free edge lies in a plane parallel to the bottom of the 
box, so as to minimize the danger of breakage, or injury to 
the box. 

Battens — Battens and cleats are very much alike. Either 
or both are put on some styles of boxes when they are made, 
or later to give additional strength. They may be on the inner 
or outer surface of a box. (See Plates HI and VHL) Cleats 
and battens on the outer surface usually increase the displace- 
ment and increase the cost, and often interfere with the stack- 
ing of the boxes. They should be used, therefore, only when 
no other method of construction can be devised which will 
be as economical and as satisfactory. 

Hand-holds and Handles — It is desirable to have hand- 
holds or handles on many boxes, such as those to contain 
heavy commodities which must be handled with reasonable 
care, and commodities of delicate construction like scientific 
instruments. Returnable boxes should also have hand-holds 
or handles, as this construction tends to encourage careful 
handling. 

Two common types of hand-holds are shown in figures 1 
and 3, Plate VI. Being near the points of the nails holding 
the tops to the ends they weaken the ends in such a manner 
as to increase the danger of failure along the lines passing 
through the length of the hand-holds. 



BOX DESIGN 63 

One method of arranging a hand-hold on boxes of Styles 
2, 2^, and 3, Plate III, is to shape the lower edge of cleats 
5-1 and 6-P as shown by the section in figure 2, Plate VI. 

A method of applying rope handles to boxes is shown in 
figure 4, Plate VI. Three methods of fastening the cleats to 
the ends have been used as follows: four No. 11 flat-head 
M'ood screws, 1^ inches long, six 7d cement-coated nails 
driven through and clintched, and four No. 11 drive screws, 1^ 
inches in length. Wood screws must be properly driven with 
a screw driver^, as driving with a hammer to any appreciable 
depth seriously reduces their holding power. The cleats are 
\y% inches thick and the ends ^f inch thick. The rope is 
three strand and is ^ of an inch in diameter. Both types of 
screws are arranged as shown in figure 4, Plate VI. It should 
be noted that in each case two nails or screws pass through 
that part of the rope within the vertical groove of the cleats 
and the lowest of these two screws or nails is about 2 inches 
from the end of the rope. The grooves in the cleats should 
be of such size that the rope is squeezed when the screws or 
nails are driven home. Tests consisting of a pull on the rope 
in a direction perpendicular to the box ends have shown that 
the nailed construction (six 7d cement-coated nails per cleat) 
offers the greatest, and the drive screw (four No. 11 drive 
screws 1^-4 inches long) the least resistance to failure, the 
wood screws (four No. 11 flat-head wood screws IV^ inches 
long) giving intermediate results. 

Webbing has been recommended as a substitute for rope 
in handles. One style is shown in figure 6, Plate VI. The 
end piece of the box is slotted and the webbing is passed 
through these slots and nailed on the inner surface of the box. 
Several large-headed nails should be used and may be driven 
through and clinched. Handles of this type have sustained 
an average direct pull before failure of 800 pounds in a direc- 
tion perpendicular to the end of the box. 

Another method of attaching webbing handles is shown 
in figure 5, Plate VI, in which the webbing is passed through 
^-inch round holes and the ends secured by nails. Such 
handles have sustained a direct pull of 700 pounds perpendic- 
ular to the end of a box. These handles are made of seven- 
cord cotton rein webbing y^ inch thick and 1^ inches wide. 
One of their advantages over rope handles is that cleats are 



'See figures 3 and 4. Plate XIV. 
-See table on page 59. 



64 



WOODEN BOX AND CRATE CONSTRUCTION 



not needed to hold the webbing and, therefore, it is possible 
to construct a box with greater volumetric efficiency. 

Many styles of metal handles can be obtained from man- 
ufacturers of trunk and chest hardware. One objection to 
many types of metal handles is that in case a box or chest 
drops on an end, the handle usually extends in such a position 
as to get the full force of the impact, which in many instances 
crushes in the end of the box or breaks the handle. 



CHARACTERISTICS OF THE VARIOUS STYLES OF BOXES 

Nailed Boxes — In Style 1, Plate III, boxes, the grain of 
the ends and sides runs approximately parallel to the top and 
bottom surfaces. One of the common failures in this type of 
box is splitting of the ends and sides, or failure of the joints 
in these parts, since the only resistance to such failures lies 
in the strength of joints,^ if present, or the strength of wood 
in tension across the grain, which is not large and is extremely 
variable in any species of wood. The smaller holding power 
of nails driven into the end grain of wood, i. e., with their 
shanks parallel with the grain, as compared to side grain nail- 
ing is a source of weakness in the joints between sides and 
ends. 

To improve on Style 1 ends and guard against the lia- 
bility of complete failure from splitting of ends and sides, 
rectangular and sometimes triangular corner cleats (Style 5) 
are added inside when the character of the contents permits. 
This construction does not increase the displacement of the 
box and is, therefore, not objectionable in that respect. If 
these cleats can be made large enough the sides may also be 
nailed to them, which of course increases the strength of the 
nailing at this point. These inside cleats should be shorter 
than the inside depth of the box, so that if the sides and ends 
shrink- the cleats will not cause an opening of the joints be- 
tween the bottom and ends. 

The most common method of preventing box ends from 
splitting and of supplementing the holding power of nails 
driven in the end grain is the addition of two outside cleats 
on each end as shown in Style 4, Plate III. These cleats 
should be long enough to come nearly flush with the outer 
surfaces of the top and bottom. They will thus aid in keep-, 
ing the top and bottom in place and will also take some of 

Tor discussion of joints see page 43. 
-See page 22. 



BOX DESIGN 65 

the thrust if a box is dropped on a corner. If a box is con- 
structed with the ends of these cleats made exactly flush with 
the outer surfaces of the top and bottom, and shrinkage occurs 
later, it may cause the ends of the cleats to project beyond 
the top and bottom ; and they may be pulled loose if the box 
is slid in such a way that the ends of the cleats catch on some 
object. This failure' is more apt to happen with heavy boxes 
and with boxes that are handled in chutes and slides. The 
amount that the cleats should be cut short to allow for shrink- 
age depends on the moisture content of the lumber when the 
box is constructed and the storage conditions afterward^ 
Usually an allowance of from ]4, to yV of an inch at each 
end will be sufficient. 

The reason for the two additional horizontal cleats 5-1 
and 5-3^ on Style 2 (Plate III) is to give increased nail-hold- 
ing power to the end of the box. The greatest increase in 
nail-holding power will be obtained when the cleats are made 
of the denser woods. The usual failure in these ends is a 
split along the inner edge of cleats 5-1 or 5-3, which allows a 
cleat with part of the end board to pull away with the top or 
bottom. The resistance to such failure is due to the strength 
of the end board in tension supplemented by the action of the 
vertical cleats. In Styles 2 and 2^^ it is possible to get more 
nails in the vertical cleats near the top and bottom edges of 
a box than in Style 3, which more effectually prevents the 
box end from splitting adjacent to the edge of the horizontal 
cleats. 

The vertical cleats in Styles 2 and Z^A should also be cut 
slightly short, so that if shrinkage occurs in the end pieces 
these cleats will not hold the top and bottom and allow the 
end boards to pull away. Style 2^/^ also has the advantage 
that when the bottom and top are being nailed to the ends the 
notches or steps on the vertical cleats take the thrust that 
would otherwise come on the nails holding the horizontal 
cleats. In some cases, as when driving several nails into a 
cleat made of dense wood, this thrust is very severe. 

In manufacturing boxes with square ends Style 3 has the 
advantage that all four cleats are the same length, hence in- 
terchangeable. When a very symmetrical end is desired rather 
than the strongest end the mitred cleats are preferred. 

Inasmuch as one of the chief functions of cleats in many 



^See page 22. 

-'See figures 3 and 4, Plate XIV. 



66 WOODEN BOX AND CRATE CONSTRUCTION 

boxes is to provide additional nail-holding- power in the box 
ends,- it is desirable that the cleats and end boards be the 
same thickness, so that the same sized nails may be used in 
them. 

The Hardware Type of "three-way" corner construction 
of box shown in figure 3, Plate XIV, is largely used for hard- 
ware. This type is well adapted to boxes carrying heavy 
loads ; and for boxes in which the maximum dimension is not 
more than two times the minimum dimension. It is better 
practice, however, to have the dimensions as nearly equal as 
possible. When the difference between the minimum and 
maximum dimensions becomes excessive some other style of 
box or crate should be used. All the faces must be made of 
material of the same thickness ; and since all nails are driven 
into the edges of boards constituting the faces of the box, it is 
necessary that the material be thick enough to prevent its 
being split by these nails. It is not considered feasible to 
make a box of this type out of material less than ^ inch in 
thickness. 

An advantage of the "three-way" construction is that 
each face has nails driven in it in two directions, those driven 
through its ends perpendicular to its face being at right angles 
to those driven into and perpendicular to its edges. A fur- 
ther and probably greater advantage is that nails are driven 
into the side grain of the wood. 

One objection to the "hardware type" of box is that in 
closing it after packing, four edges must be nailed. The 
boards meeting at these edges are so arranged that nails must 
be driven in three directions, which makes much turning and 
handling of the box necessary, especially if a nailing machine, 
is used for the work. In closing other types of nailed boxes, 
the nails are all driven in one direction even though they may 
be distributed along four edges of one face. 

Lock-Corner Boxes — The box shown in Style 6, Plate 
III, is of a type in which the sides and ends are joined by a 
series of tenons which interlock and are called "locks." 

These locks are held together by gluing and the top and 
bottom are fastened in some other way. This method of con- 
struction allows the use of thinner material in the ends than 
is possible with a nailed box (Style 1) properly designed for 
carrying the same contents. The lock corner, if properly 
glued, gives a more rigid box than nailed corners, there being 
no appreciable distortion before failure occurs. In lock-cor- 



1 



BOX DESIGN 67 

ner boxes there is danger that the ends and sides will split 
open, or that failure will occur in the joints which may be 
present in these ends and sides. ^ Since the ends can be made 
of thinner material in the lock-corner boxes than in nailed 
boxes, there is danger that the desire to save material may be 
carried to extremes, with the result of making the end too 
thin for properly nailing on the top and bottom. 

Tests show that in lock-corner boxes a considerable num- 
ber of the failures occur because the nails pull from or split 
the edges of the thin ends, locks open, ends split, and matched 
joints lack sufficient strength. The ends of lock-corner boxes 
are longer than those of nailed boxes because of the addi- 
tional length necessary for forming the locks. This extra 
length is equal to twice the thickness of the side boards plus 
enough for trimming after gluing. The sides also need enough 
extra material for trimming after gluing. 

Dovetail Boxes — The dovetail construction shown in 
figure 2, Plate VII, is used to a limited extent for expensive 
boxes, returnable boxes, che'sts, etc., but such construction is 
more common in cabinet work and furniture. The top and 
bottom of the boxes may be fastened by any desirable method. 
In figure 1, Plate VII, are shown the tenons as they appear 
on two pieces before being joined to form a corner. 

One point of superiority of the dovetailed corner in com- 
parison with the lock-corner is the advantage of the wedging 
action in preventing failure as described in connection with 
Style 6, Plate III, but it requires more complicated machinery 
to produce the dovetailed corner. 

The disadvantages due to thin ends, joint failures, etc., 
in dovetailed corners are very similar to those in lock-corners. 

Wirebound Boxes^The stock in the sides, top, bottom, 
and ends of the boxes shown in figures 1 and 3, Plate VIII, is 
called sheet material and it is usually made of rotary-cut 
stock, although resawed lumber is used occasionally. 

Figure 4, Plate VIII, shows a mat for a "4-one" box as 
delivered by a stitching or fabricating machine ready to be as- 
sembled with the end panels, or shipped in this form to the 
consumer. The cleats are held to the sheet material by the 
staples which pass over the wires, through the sheet material, 
and have their points firmly held in the cleats. Staples not 
driven into cleats are clinched on the inside surface of the 
sheet material. Staples over all wires should be spaced from 



'See papre 43 for discussion of matched joints. 



68 WOODEN BOX AND CRATE CONSTRUCTION 

1^4 to 2}i inches apart. It has been found that with l-^'^-inch 
spacing, the end binding wires do not slip off the corners of 
the box as frequently as when the spacing is larger. The end 
pieces are stapled or nailed on the inside surface of three of 
the cleats when the box is assembled, the remaining cleat on 
each end being attached only to the top as shown in figure 6, 
Plate VIII. The binding wires are twisted together near one 
edge of a side, to close the box. 

There are several styles of end joints for the cleats in 
-wirebound boxes. The mortise and tenon now in general use 
and the step-mitre are shown in figure 4, Plate VII. The 
step-mitre is the older method but has at the present time 
been almost entirely abandoned in favor of the mortise and 
tenon joint. Cleats with plain mitred ends are also coming 
into use. They are more economical to manufacture than 
other types and are very satisfactory for containers for some 
commodities. 

An advantage of the step-mitred and plain mitred cleats 
is that they allow staples to be driven much nearer the ends 
of the cleats, which aids materially in preventing the binding 
wires from being forced off the corners of the box. An ad- 
vantage of the mortise and tenon joint is that it prevents 
lateral movement of the cleats respecting each other and thus 
makes a box which is more rigid than one made Math either 
style of mitred cleats. 

Cleats for the smaller wirebound boxes are usually made 
approximately ^ by {f inch in cross section. The resist- 
ance of the box to destructive hazards encountered in service 
is only slightly improved by increasing the width of the cleats 
to Ij^e inches. 

The end construction of wirebound boxes may be mate- 
rially strengthened by the addition of battens. The size, num- 
ber, position and method of fastening battens depends very 
largely on the severity and location of the thrusts transmitted 
to the ends by the contents of the boxes. An arrangement of 
battens which has been tested at the Forest Products Labora- 
tory is shown in figures 1 and 2, Plate VIII. These battens 
protect and strengthen the end material, increase the rigidity 
of the box, add strength to the box to resist vertical compres- 
sion, such as occurs when a box is subjected to an exterior 
load as in the bottom layer, make the corner construction 
more rigid, and tend to maintain the relative position of the 
cleats in the step-mitre construction, and also in the mortise 



BOX DESIGN 69 

and tenon construction after either the tenon or the sides of 
the mortise have failed. The amount of strength added by 
these battens increases as the width of the battens increases 
to a maximum, varying" from 1^ to 2 inches. The thickness 
remains constantly equal to that of the cleats. Battens much 
smaller can not be properly nailed and neither larger battens 
nor solid ends add appreciably to the serviceability of a box, 




Fig. 21 — Nailed box showing panel style of construction. 

as the ends are then too strong and out of balance with the 
other parts. In any case, battens must be securely nailed in 
order to get the greatest increase in strength. The battens 
on the Fassnacht type of box, figure 1, Plate VHI, have a 
tenon on each end and a tongue on one edge which fit into 
grooves in the edges of the cleats. This construction mate- 
rially assists the nails in holding the battens in place. 

Inside liners or corner cleats, as shown in figure 5, Plate 
Vm, strengthen the box to some extent. 

The sheet material of wirebound boxes is rather easily 
punctured by the corners of other boxes and projecting ob- 



70 WOODEN BOX AND CRATE CONSTRUCTION 

jects, and is not adaptable for commodities which are Uablc 
to be seriously injured by such hazards. 

Wirebound boxes are made of thin material, and are, 
therefore, economical in the use of wood. They can be 
shipped in the mat (figure 4, Plate VIII) or knocked down 
form, and can be assembled at the point of filling with less 
work than is required to nail shooks^ together. They weigh 
less than other wooden boxes adaptable to the service and 
made of the same wood. Special tools have been devised for 
efficiently twisting the wires for closing wirebound boxes. 

Panel Boxes — Boxes of the type shown in figure 21 are 
used to a considerable extent. The panels are made of ply- 
wood, three-ply stock being most generally used. The ply- 
wood is nailed to cleats or battens at each edge to form the 
panels and these panels are then nailed together through the 
cleats to form the box. This construction makes a box of 
light weight which if properly nailed is much tighter and 
more rigid than a wirebound box. Since the panels are of 
plywood, the weakening effect of a defect which occurs in 
one of the plies is largely annulled by the adjacent sound 
material of the other plies. The construction is, therefore, 
more uniform than any type of box made of the common 
grades of box lumber or single-ply veneer. 

Plywood equal in thickness to lumber offers much more 
resistance to puncturing and therefore is more desirable for 
boxes carrying commodities which will be damaged by that 
hazard. Plywood also shrinks very little, and does not split 
or pull away from nails. 

FACTORS DETERMINING THE AMOUNT OF STRENGTH 

REQUIRED 

Contents — With contents made up of • an equal number 
of units, identical in size and shape, having similar properties 
but different weights, and packed in boxes of the same inside 
dimensions, it is evident that the heavier commodity will re- 
quire a stronger box to withstand equivalent amounts of 
rough handling. 

The details of a box to give this additional strength can 
be most readily determined by a series of tests on various 
boxes of dift'erent design. Contents which will themselves 
absorb considerable shock will materially prolong the life of 

^The ends, tops, bottoms and sides of wooden boxes before assembling are 
called shocks. 



BOX DESIGN 71 

a container. It has been demonstrated by tests that a box 
containing 60 pounds in No. 3 food cans will fail more quickly 
under test than an identical box filled with the same weight of 
sand and sawdust in bulk. 

Thus the nature of the commodity or inner containers 
has a marked influence on the degree of strength required in 
a box for performing a specified service. 

If a box is packed with contents consisting of a few units 
of rectangular section there is a tendency for these units 
to maintain their relative positions and thus prevent bending 
of the box boards because of the arching effect produced. 

Boxes for carrying one rigid object of rectangular shape 
need form only a protecting envelope with perhaps little 
strength. Thus the strength of a box in some respects may 
be diminished in proportion to the amount of resistance 
offered by the contents to injury and deformation. 

Hazards of Transportation — Nothing has more influence 
on determining the degree of strength required in a box than 
the hazards of transportation. They usually tend to cause 
failure in boxes by one or more of three actions, viz., weav- 
ing or wrenching, puncturing or breaking various parts, or 
collapsing.^ The collapsing action may occur as diagonal 
compression between opposite corners or opposite edges, or 
as compression perpendicular to the ends, sides, top, and bot- 
tom. Boxes which are dropped, thrown, and rolled when 
being handled by hand may encounter all of these hazards, 
the severity of which will depend on the care exercised in do- 
ing the work. The hazards that boxes are subjected to in 
being conveyed by motor trucks in long distance transporta- 
tion may result in considerable twisting, weaving, and jam- 
ming of the boxes, and there may be destructive compressive 
stresses transmitted to the boxes at the bottom of the load. 

The hazards of shipping by freight are at times very 
severe, especially those occurring during the switching and 
making up of trains. In cars containing a miscellaneous lot 
of commodities, loaded with little thought of proper arrange- 
ment and blocking so that the stronger packages should re- 
ceive the severest strains, there will most surely be a large 
loss from damaged goods. The contents of cars, if not well 
braced in position, receive severe weaving and wrenching 
strains and may also be subjected to serious compressive and 
puncturing stresses. 

^See page 60. 



72 WOODEN BOX AND CRATE CONSTRUCTION 

Destructive conditions due to the elements, especially 
moisture, are apt to be experienced by boxes in transit. Such 
conditions may be encountered at loading" points where plat- 
forms and wharves are not covered, at prepaid shipping 
points in the country where there are no railroad agents, and 
in transit by boats, barges, trucks, wagons, pack animals, and 
refrigerator cars. 

The strength requirements for export shipment are much 
greater than for domestic shipment ; in fact, export shipments 
may undergo all the hazards of domestic shipments previous 
to arriving at the wharf for loading; and after reaching a for- 
eign port there may be a long journey inland. 

The stevedores who handle export shipments pay little 
attention to proper handling of freight, with the result that 
weak packages and those containing fragile materials are 
tossed and thrown about with heavier and stronger ones. 
Cargo hooks are indiscriminately used on packages, which 
are punctured by them and the contents injured. In many 
foreign ports the stevedores are people who can not read 
directions that may be printed on packages regarding the 
nature of the contents and directions for handling, and thus 
all containers are treated much alike. 

One method of loading and unloading ships is by the use 
of cargo nets. These are large nets on which a quantity of 
boxes are piled and the corners of the net then drawn together 
for lifting in loading and unloading. In these operations the 
boxes are thrown violently together in the nets and in swing- 
ing into place over the ship or lighter the load net often 
strikes severely against the side of the ship, or some other 
object, with resulting injuries to the contents of the net. In 
emptying the net, one edge is often released several feet above 
the deck, the contents falling the remainder of the distance, 
accompanied by a rolling action. Boxes must be well con- 
structed to endure such service. 

Rope, slings, chains, and grappling irons are used on 
large, heavy boxes. The chief hazards connected with their 
use are dropping due to premature releasing of the hoisting 
device, crushing and bending action due to the manner of 
applying slings, etc., and striking against other objects in 
swinging from one position to another. Such hazards are 
very common and provision must be made for resisting them 
in boxes for export shipment. 

In many harbors the ships must be unloaded by means 



BOX DESIGN 73 

of lighters. This means extremely severe handling", especially 
at ports where a rough sea is common. An extra handling 
is then necessary from the lighters to wharves. 

The hazards of a sea voyage are the stresses resulting 
from improper stowage in the ships, the shifting of a cargo, 
and weakening effects due to change in moisture content and 
corrosion of metal parts. 

FACTORS DETERMINING THE SIZE OF A BOX 

Gross Weight — The gross weight for boxes should, if 
possible, be such as will make a reasonable load for one man 
or, in some instances, for one woman. The French Govern- 
ment in connection with war work fixed the maximum load 
for a woman at seventy pounds. When the load must be 
more than one person can handle efficiently it should, if pos- 
sible, be increased to make a reasonable load for two. If the 
gross weight is too much for one person and too light for two 
the work of handling can not be so efficiently done. The 
weight of the container should be as small as proper design 
will permit with the object of saving in freight charges and 
box material. 

Desired Quantity — With some commodities it is the 
quantity which is ordinarily desired by the consumer which 
will determine the size of the box to be used. With small 
boxes, however, several of them may be in turn packed in a 
larger box or crate to facilitate handling and to give better 
protection in shipping. 

Nesting, Disassembling, or Knocking Down Contents — 
For some objects, the size of the box must be larger than is 
ordinarily desired for convenient handling ; in such cases, as 
much nesting and disassembling of parts should be done as is 
deemed advisable in order to reduce the size of the box. Dis- 
assembling will often allow parts that would be easily broken 
to be packed more securely. 

Minimum Displacement — In every case, the amount of 
space required for a box, i. e., its displacement, should be as 
small as possible. This is especially desirable for export ship- 
ments, as rates are based on the space required rather than 
the weight. Probably the space recjuirement will enter more 
directly into rates for domestic shipments in the future. 
Minimum displacement also means in most instances the use 
of a smaller amount of material in constructing the boxes 



74 WOODEN BOX AND CRATE CONSTRUCTION 

and a reduction in storage space required for them, both in 
shook and assembled form. 

Traffic Limitations — There are certain traffic limitations 
and regulations which influence the design of some boxes. 
The design of boxes for shipping explosives and dangerous 
articles by freight is regulated- by the Interstate Commerce 
Commission. The size and weight of packages for shipment 
by parcel post is limited. More definite regulations by traf- 
fic officials regarding the method of boxing and packing cer- 
tain commodities would help to solve the problem of obtain- 
ing more adequate shipping containers. 

SPECIAL CONSTRUCTIONS 

Protection of Fragile and Delicate Contents — Many com- 
modities are extremely susceptible to damage in transit ; too 
much information can not be had by box designers regarding 
methods of packing such commodities correctly. 

Protection against injury by moisture must be provided 
for some commodities. One method is to provide a water- 
resisting paper liner, or a tight sheet-metal liner. When these 
liners are to be used, the space which they require must be 
provided for in the design of the box. 

Some kinds of merchandise need to be packed in mate- 
rials that will not transmit to the contents the shocks and 
impacts received by the box. Among such packing materials 
are corrugated fiber and straw board, excelsior, straw, hay, 
shavings, sawdust, etc. The amount of space required for 
these cushioning- materials will depend on the fragility and 
weight of the commodity and the severity of the hazards of 
transportation. 

One method of preventing serious stresses and shocks 
due to boxes falling on their corners is to provide each corner 
with a bumper of cushioning material. Another method is 
that of "flotation," which consists of packing one box within 
another, with the intervening space between all faces of the 
boxes filled with a cushioning 'material or some system of 
mechanical spring supporters. In this problem two boxes of 
proper relative size and strength must be designed and the 
cushioning feature must be provided for. 

The various individual elements constituting the con- 
tents of some boxes need to be prevented by separators of 
some character from jolting. against each other. One method 



BOX DESIGN 



75 



is to form a series of cells or individual compartments for 
each element of the contents, as shown in figure 22. Tests 
have demonstrated that for carrying hand grenades cells made 
from corrugated fiber board sustaining 175 pounds per square 
inch before puncturing, as recorded by the Mullen, the Webb 
and other similar testers, are more efficient than wooden cells 




Fig. 22 — Box with corrugated fiber board lining and cells. 

made from j;^g^"ii''ch lumber. The wooden cells broke up 
sooner and absorbed less shock than the corrugated fiber 
board cells and thus they transmitted the shocks of the con- 
tents to the container, thereby stimulating the action tending 
to injure the contents. 

The character of the material composing the cell will de- 
pend on the nature of the contents to be packed. Some con- 
tents need to be protected from surface abrasions only, and in 
such cases it is the cushioning property that is desired in the 
cell walls ; for other contents, much strength may be needed 
in the cell walls, as the contents may not be strong enough 
to withstand the pressures which occur within the container. 

Whatever the material of which the cell is made its di- 
mensions should be such as to permit the contents to fit snug- 
ly; this diminishes the force of the impacts tending to de- 
stroy both the cells and the container, and also allows the 
total displacement of the container to be reduced. 

In designing boxes for some commodities the more fragile 
and delicate parts must be separated from the stronger parts 



ie WOODEN BOX AND CRATE CONSTRUCTION 

by partitions of considerable strength. In some instances, the 
amount of material in a box can be reduced and a more satis- 
factory container secured by using one or more partitions. 
Partitions may be placed horizontally as well as vertically 
and also may be left unfastened so as to facilitate removal. 

Some articles can be shipped to advantage by using trays 
for supporting them in their boxes. Trays may be constructed 
of plywood or of lumber. In using lumber for trays in some 
instances it is well to put splines in their ends to prevent split- 
ting and, to some extent, warping. There is much less 
change in size and shape of symmetrically constructed ply- 
wood than lumber when subjected to change in moisture con- 
tent. It may be desirable at times to use sheet metal, wall 
board, etc., for trays. 

When several articles of varied shape with some delicate 
parts attached are to be packed in the same box, a series of 
internal braces, supporters, separators, etc., will have to be 
designed. Good examples of such boxes are those for carry- 
. ing rifles, machine guns, valuable tools, scientific instruments, 
and machines. 

Vermin — Some commodities are attacked by various 
species of vermin in storage and transit, especially during 
sea voyages. It may devolve on the box designer to devise a 
style of box construction or inside lining which will resist 
the ravages of such destructive pests. 

Thieving — Great losses occur from theft while goods are 
in transit. The problem is a very serious one and much at- 
tention should be given to the design of boxes which can not 
be readily opened and reclosed without detection. 

The prevention of thievery is largely a matter of police 
protection. Seals, straps, and more rigid construction as de- 
scribed in other parts of this book are valuable in that theft 
is more quickly . discerned, and the thief is deterred by his 
knowledge of the box construction. 



CHAPTER III 

CRATE DESIGN 

Factors Affecting Strength of Crates — Factors Determin- 
ing Amount of Strength Required in Crates — Factors 
Influencing the Size of Crates. 

Many of the factors influencing the details of design for 
boxes will similarly affect the design of crates. Among these 
are the availability, supply, and cost of lumber, manufactur- 
ing limitations, and balanced construction which are discussed 
in Chapter II. 

FACTORS AFFECTING STRENGTH OF CRATES 

Influence of Styles of Crates on Strength 

The serviceability of crates is vitally affected by the style 
of construction, especially the method of joining the frame 
members at the corners of the crates and the kind of fasten- 
ings used. 

Types of Corner Construction — In Figures 1, 2 and 3, 
Plate XI, are shown three types of the "three-way" corner 
construction for joining the frame members of crates. If 
only the types of construction are considered, that shown in 
figure 1, Plate XI, is the most desirable because all of the 
frame members are fastened in the same way. In figures 2 
and 3, Plate XI, the arrangement of the members is differ- 
ent ; but these types may be desirable when crating some ob- 
jects. Material which is approximately square in cross sec- 
tion is preferred in these two constructions. There are sixteen 
different variations of the three-way corner. (See Plate XII.) 

An advantage of the three-way corner is its symmetrical 
construction in which the members are fastened together in 
such a way that through each member nails or bolts may be 
passed in two directions at right angles to each other, thus 
uniting the members securely and reducing the danger of 
their being split by the bolts or nails; nails or bolts passing 



78 WOODEN BOX AND CRATE CONSTRUCTION 

through the members in one direction resist the splitting ac- 
tion of those at right angles to them. 

Another advantage of the three-way corner is the arrange- 
ment of the members so that only one thickness of frame 
material intervenes between the contents and the outer sur- 
face of the crate, thereby in most cases keeping the displace- 
ment lower than is possible with other styles of crates. 

In figure 5, Plate XI, is shown a type of crate-corner 
construction which is largely used but which is inferior to 
the three-way corner construction in at least two respects ; 
viz., there are two thicknesses of the material outside the ob- 
ject on two faces of the crate, which increases the total dis- 
placement of the crate, and some of the members have nails 
through them in only one direction, so that they are not held 
so securely to the other members as they would be with the 
three-way corner construction. The addition of a second 
piece along one edge, as shown in figure 6, Plate XI, gives 
additional strength to the corner, makes the combined mem- 
ber stiffer and stronger, and, in some instances, gives addi- 
tional support and protection to the contents. 

Frame Members — The frame members of a crate as shown 
in figures 3 and 4, Plate XIII, constitute the foundation to 
which all other parts are connected either directly or indirectly. 
The frame members must have sufficient size and strength to 
form a foundation skeleton upon which to complete a crate 
that will carry the contents to its destination with little danger 
of injury, even though severe hazards are encountered. Not 
only the vertical and horizontal members should be strong 
enough to support the exterior loads to be put upon a crate in 
storage or transit, but also the diagonal and cross bracing^ 
must be sufficient and so arranged as to distribute the stresses 
and hold the other crate members in proper position. Without 
proper bracing it is practically impossible to build a crate that 
will not weave or skew in transportation, even though the 
three-way corner construction is used and the crate when 
freshly made appears quite rigid. This skewing and weaving 
is largely responsible for such damage as rubbing of varnished 
surfaces, and the breaking of legs and other projecting parts 
of furniture. 

The amount that any piece will support in compression, 
considering that it is a column so short or so firmly braced 
that there is no danger of failure by buckling or bending, will 

^See page 84 relative to internal braces. 



CRATE DESIGN 79 

be found by multiplying- the area of the cross section of the 
piece in square inches by the safe allowable load for the mate- 
rial in pounds per square inch.^ The safe allowable load is 
always considerably less than the ultimate load that a mate- 
rial can support. The horizontal top members must be strong 
enough to sustain between points of support such bending 
loads as may be placed on them in storage or shipment. 

Skids — The lower horizontal frame members running 
lengthwise of a crate usually form the skids. The skids sup- 
port the contents directly, or indirectly through intervening 
members, and also the weight of the crate and superimposed 
loads, unless the lower ends of the vertical members rest on 
some other support. For heavy objects, which must be 
moved on rollers and hoisted with chains or slings, the skids 
should have extra pieces added to them as shown in figure 4, 
Plate XIII, which will increase the bending resistance and 
provide a bearing surface for the rollers, chains, etc. The 
ends of these additional pieces should be beveled or scarfed 
to facilitate sliding or the passage of the skids onto rollers, 
and should also extend outward underneath the vertical mem- 
bers of the crate to support them as indicated, for otherwise 
any load put on the crate will produce compression and shear 
on the fastenings which connect the vertical members to the 
skids. These extra pieces must also be securely fastened 
throughout their length to the frame members in order to 
make the combined parts act more nearly as a single piece 
skid, which increases the resistance to horizontal shear and 
bending. When a crate is being moved, it may at some time 
be supported by rollers or slings in such a way as to produce 
serious bending moments in the skids. To calculate the 
weight that a skid will support when resting on a roller mid- 
way between points of loading, the formula for beam loading 
given in U. S. Department of Agriculture Bulletin 556, 
"Mechanical Properties of Woods Grown in the United 
States," may be used. 

Bracing Long Crates — When, in a long crate, each skid 
and the top horizontal frame member are securely fastened 
together by several cross members and substantial diagonal 
or cross braces are provided, a truss-like form of construction 
is obtained which greatly increases the resistance of the crate 
to bending. A side view of such a crate is shown in figure 1, 



'See United States Department of Agriculture Bulletin 556, "Mechanical Prop- 
erties of Woods Grown in the Unitsd States," 10 cents per copy, obtainable from 
Superintendent of Documents, Washing-ton, D. C. 



80 WOODEN BOX AND CRATE CONSTRUCTION 

Plate XIII. To obtain the number of cross members and 
number of angular braces or sets of cross bracing for any 
face of a crate, use the following rule : 

Divide the longer dimensions of any face by its shorter 
dimension, and, 

1. If the result is less than one and one-half use one 
angular brace or one set of cross bracing ; 

2. If the result is one and one-half or more and less than 
three, use one cross member and two angular braces or two 
sets of cross bracing; 

3. If the result is three or greater, use a number of 
angular braces or sets of cross bracing equal to the largest 
whole number in the result. The number of cross members 
will be one less. (See figures 1 and 2, Plate XIII.) This 
method of figuring the number of braces to be used divides 
the face of the crate into panels which are approximately 
square, the braces making angles of about 45 degrees with 
horizontal members, which is considered the best practice. 

Fitting and Fastening Braces — In cutting the end of a 
diagonal or cross brace, the toe should be made with a flat 
surface or butt against the adjacent member. (See figure 4, 
Plate XL) Care should be exercised, however, that the 
distance from the toe to the heel is great enough to provide 
for properly nailing or bolting the brace. 

The thickness of a diagonal brace, or a set of cross braces, 
figure 4, Plate XIII, plus the thickness of sheathing when 
used, figure 2, Plate XIII, should not exceed the thickness of 
the frame members. 

When cross bracing is put on as in figure 4, Plate XI, 
the outside ^race should have blocks between its ends and 
the frame members to which it is nailed unless the length of 
the brace is such that the amount of bending produced by 
omitting the blocks will not seriously strain the braces. The 
initial bending produced by omitting the blocks will tend to 
increase the danger of failure by buckling when a brace is 
subjected to endwise compression. Such blocks as are used 
under braces should preferably extend for some distance 
along their length and be securely fastened to them to min- 
imize the danger of the blocks being split and getting out of 
place. Cross braces should be securely fastened together at 
the point of intersection. Nails driven through and clinched, 
or bolts, are preferable for this fastening. 

Scabbing — In figure 2, Plate XIII, the use of scabbing is 



CRATE DESIGN 81 

shown. Scabbing consists of a piece nailed across a joint on 
the faces of two pieces to unite them securely. It is similar 
to a plaster joint in a timber construction. The chief require- 
ments of pieces which are to be used for scabbing is that they 
possess sufficient strength and resistance to being split or 
sheared by nails or bolts. It is well to have the scabbing in 
this particular construction wide enough to support the sides 
of the toes df the braces, as indicated in the figure. 

Sheathing — The purpose of sheathing is to protect the 
contents from the elements, reduce losses of small parts by 
thieving, and prevent injuries to contents from external ob- 
jects. Sheathing when securely nailed also strengthens a 
crate to a considerable extent, especially if it is run in a 
diagonal direction. It may be put entirely outside of the frame 
members and bracing-. A poorer grade of material can be used 
for sheathing than for the other parts of a crate. Usually 
matched lumber surfaced at least on one side and with the 
surfaced side exposed to receive shipping directions and ad- 
vertising is preferred. 

Battens on crates are used for additional supports for 
sheathing and iuv holding on waterproof coverings. 

Physical Properties of Wood Affecting Strength. 

Relative Thickness of Material — For general crating wc^rk 
the harder woods of Groups 2, 3, and 4^ may be 25 per cent 
less in thickness than material from Group 1 to give approx- 
imately equal strength. 

Moisture Content — The moisture content in crate lumber 
should be within limits of from 12 to 18 per cent. Decreases 
in moisture content after construction will loosen the fasten- 
ings and joints, cause members to check, allow internal braces 
to become loose, and diminish the effectiveness of the sheath- 
ing as a protection to the contents. 

Defects — In crate members and braces, defects must be 
more rigidly excluded than in lumber for boxes, as the parts 
must have more uniform strength. Except in special cases, 
such defects as are allowed in box material can be permitted 
in crate sheathing. Defects are discussed fully in Chapter II. 

Nailing and Bolting Qualities of Wood — Since the main 
fastenings in crates come at tlie ends of the Nariou'^ members 
it is important that lumber which is not easily split by nails 

^See page 100 for grouping of woods for bo.x construction. 



82 WOODEN BOX AND CRATE CONSTRUCTION 

or bolts be used. It is a well-known fact that in many wooden 
structures the great weakness and danger of failure is due to 
inability to get the ends of the various members in tension 
fastened in such a way as to stress them even to a point of 
safe loading. For crate construction, lumber which is warped 
or twisted is more objectionable than similarly affected mate- 
rial would be in box work. Considerable initial stress is 
produced in a seriously warped timber when it it is forced to 
assume approximately a normal shape. This necessarily re- 
duces the ability of the piece to resist external forces. 

The various factors which influence the holding power 
of nails and the strength of nailed joints are discussed on 
pages 51 and 101. 

Bolts, when holes of proper size are bored for them, 
do not produce a wedging action which tends to split the 
members of a crate as do large nails or spikes. The clamping 
action produced by bolts holds the members together more 
securely than nails, which are dependent in such action upon 
the friction of their shanks in the wood of the member hold- 
ing the points. In case of shrinkage and splitting of the 
wood, bolts may be tightened and will continue to be more 
effective than nails under similar conditions. 

Fastenings and Reinforcements — Because of the open 
construction of crates the total amount of space allowed for 
fastening is less than for boxes of the same size and there- 
fore the fastenings on crates must be relatively stronger. 
Much of the discussion, however, pertaining to nails in the 
section on "Fastenings and Reinforcements," page 53, will ap- 
ply to the nails used in crating work. 

Nails and Nailing — The size of cement-coated nails recom- 
mended for the various thicknesses of lumber used in all 
parts of a crate is given in Table 13. 

Frame members and braces should have not less than 
two nails in any end and as many additional nails as can be 
driven without weakening the joints by splitting the mem- 
bers. Nails in sheathing should be staggered, the distance 
between their centers, measured along the length of the piece 
nailed to, being equal to y^ inch for each penny of the nails 
used. Sheathing should be nailed to all members of the crate 
which it crosses. 

It- is often supposed that driving nails at a slant results 
in an increased resistance to withdrawal and to shear in the 
joints. While in some special cases this belief is supported 



^ 



CRATE DESIGN 



83 



by test results, tests show that in most cases slanting causes 
a loss of efficiency. 

The efficiency of nails and the number of nails that can 
be used without splitting can be very considerably increased 
by boring holes. The boring of holes gives definite bearing 



Table 13 


Size of Nails for Crating 








Penny oi 


cement- 


Thickness of lumber in inches 


coated box nails' 


Against nail head 


Holding nail point 


Group I 


Group II 






woods2 


woo ds2 


1/2 


1/2 to 5/8 


6 


5 


1/2 to 5/8 


3/4 and over 


7 


6 


3/4 


3/4 and over 


8 


7 


13/16 to 7/8 


13/16 and over 


9 


8 


1 


1 and over 


10 


9 


1 1/8 to 1 1/4 


1 1/8 and over 


12 


10 


1 3/8 to 1 1/2 


1 3/8 and over 


16 


12 


1 5/8 to 1 3/4 


1 5/8 and over 


20 


16 


1 7/8 to 2 


1 7/8 and over 


30 


20 


2 1/8 to 2 1/4 


2 1/8 and over 


40 


30 



on the end grain of the wood, whereas driving without holes 
forces the wood fibers aside without afifording such definite 
bearing. Nails driven in holes slightly smaller than their 
diameter have considerably better resistance both to direct 
pull and to shear in the joint than nails driven without holes. 

Under ' the repeated shocks and more or less constant 
weaving action to which crates are subjected slender nails 
bend near the surface of the pieces joined, and without loosen- 
ing the friction grip toward the point of the nail. As the 
diameter of the nail is increased the stiffness also increases, 
and at a much more rapid rate, and the deformation, of the 
wood and decrease of the friction grip progresses toward the 
point of the nail. Consequently, the larger and stiffer nails 
are in greater danger of having their value destroyed by the 
treatment accorded crates during handling and shipment. 

Bolts and Bolting — Table 14 is from War Department 
Supply Circular No. 22, 1918, and it gives the relative size of 
bolts to be used in crate frames. There should be at least 
two bolts in each end of frame members. (See figures 1, 2, 
and 3, Plate XI.) 

Carriage bolts are usually preferred for crating work be- 
cause the heads are oval and do not catch on objects, as do 



^See nail tables on pages 139, 140. 
"Se« groups of woods, page 100. 



84 WOODEN BOX AND CRATE CONSTRUCTION 

the heads of machine bolts when not countersunk. Machine 
bolts usually require a washer under the head to give suffi- 
cient bearing surface. Carriage bolts also have the advantage 
of a square shoulder on the shank adjacent to the head, which 
prevents turning of the bolt when drawn into the wood. 
Washers, preferably standard cut, should be used under all 
nuts to prevent them from cutting into the wood. So far as 

Table 14. Size of Bolts for Crating 



Thickness of frame lumber 
in inches 


Diameter of bolt 
in inches 


1 to 1 1/2 
1 1/2 to 3 
3 and over 


3/8 

1/2 
5/8' 



possible, all nuts should be put on the inner side of joints. 
Holes for bolts should be small enough for a drive fit, which 
will make a more rigid construction. 

Lag Screws — Lag screws are not considered a good fas- 
tening in crating work. They may, however, be used should 
it be impossible to get a bolt into position and apply the nut, 
or where a bolt of excessive length would be required. In 
using lag screws, a hole should first be bored equal to the 
diameter and depth of the shank, and then the hole continued 
with a diameter equal to that at the root of the thread until 
the total depth of the hole is equal to the length from the 
head to the end of the untapered part of the thread. 

Straps — Straps may be used in strengthening crates. One 
method of strengthening a corner is shown in figure 7, Plate 
XL Straps are also used in some instances to help keep 
the contents in position and support internal braces. 

Binding Rods — Binding rods, or tie rods, may be run 
through crates in various directions to bind the parts more 
securely together. They are especially valuable in places 
where much tension is apt to be developed in the members 
and because, as has been mentioned, it is very difficult to join 
wooden members in such a way that their tensile strength 
can be utilized. 

Internal Bracing — The object of internal bracing is pri- 
marily to support the contents in the crate in such a manner 
that the crate may ride on any face without injury to the 



^In very heavy crates, bolts large than %-inch will be desirable in some 
inetances. 



CRATE DESIGN 85 

coiileiils. If the contents arc fairly ri^id such internal bracin<^ 
will then serve to strengthen the crate. 

Internal bracing should, if possible, be so placed that the 
thrusts come against the end grain of the braces, then if 
moisture content of the braces is reduced they will not permit 
as much movement of the crate contents as would have oc- 
curred had the thrust been against the side grain of the 
braces, because shrinkage of wood parallel with the grain is 
negligible. 

FACTORS DETERMINING AMOUNT OF STRENGTH 
REQUIRED IN CRATES 

The weight of the contents and their resistance to exter- 
nal forces determine to a great extent the degree of strength 
that a crate must have. If the contents are heavy and rigid, 
possessing great strength, then a crate may be largely held 
in position and its shape maintained by internal braces' set 
at various places between the contents and the crate mem- 
bers. With contents which are more delicate and possess 
little strength, the crate must have much rigidity and strength 
so that it may be depended on to support the contents prop- 
erly and prevent damage. 

Hazards of Transportation 

A crate must be strong enough to prevent damage to the 
contents from the hazards which may be encountered in its 
journey. Many American shippers at the present time have 
little conception of the severity of the hazards in export 
shipping. 

In moving crates on rollers and handling with cranes 
severe bending stresses are apt to be profluced.- Crates when 
being handled by cranes may also be drojiped or collide with 
other objects in being lifted and swung, which will twist and 
strain them severely. 

In moving crated material by wagon and trucks, the 
greatest hazards will ordinarily occur in the process of load- 
ing and unloading. 

The hazards to be guarded against in shipment of crated 
materials o\'er railroads on flat cars are movement of con- 
tents in the crate, movement of the crate on the car, theft 
of easily removed ])arts, and damage by the elements. 

'See page 84 
-See page 78. 



86 WOODEN BOX AND CRATE CONSTRUCTION 

In export shipment the hazards that are usually met with 
are very rough handling by cranes and derricks, the stresses 
that occur due to the method of stowage, cargo shifting, and 
the destructive action of the elements. 

FACTORS INFLUENCING THE SIZE OF CRATES 

The outside dimensions of a crate will depend on the 
dimensions of the contents, the amount of clearance necessary 
between the contents and the members, and the size of the 
members. As much disassembling of contents as is possible 
at a reasonable cost should be done, in order to reduce the 
space required. 

The cost of material for making crates, storage space 
required, and charges for export shipment based on space 
occupied, are some of the factors which necessitate reducing the 
displacement of a crate to the minimum. With very large 
crates the ability of the transportation machinery to move 
them to their destination without difficulty is sometimes a 
very important consideration. 

Before any large shipments are made, especially in for- 
eign trade, complete information should be obtained. The 
National Association of Box Manufacturers is in touch with 
the various sources of information as to the many require- 
ments for shipments to different foreign countries. These 
traffic requirements are so varied and voluminous that they 
cannot be included in this book. 



CHAPTER IV 
BOX AND CRATE TESTING 

Methods of Testing and Their Significance 

Data of value in the proper designing of boxes and crates 
cannot be easily obtained by observing boxes and crates as 
they proceed through the various stages of commercial serv- 
ice. Containers which have failed in service may be examined, 
but the causes which produced the failure can not be meas- 
ured or readily observed, nor can the sequence of failures be 
told. Laboratory tests, however, which closely simulate the 
hazards encountered in commercial transportation service and 
which may be completely observed through all the stages of 
the life of a box or crate as it passes through the process of 
testing, give information as to the relative value of dififerent 
details of construction. Laboratory tests can also be carried 
on more quickly and economically. 

Some of the definite phases of box and crate construc- 
tion work concerning which information may be obtained by 
testing are the following: 

L Classification of woods as to nailing and strength 
properties for box construction. 

2. Determination of balanced construction.^ 

3. Determination of the effect of different degrees of 
moisture content and changes in moisture content on the 
strength of boxes. 

4. Comparison of various methods and amounts of 
reinforcing. 

5. Comparison of different styles of construction. 

6. Determination of the effect of various types of con- 
tents and methods of packing on the serviceability of a box. 

7. Standardization of strapping of wooden boxes. 

METHODS OF TESTING AND THEIR SIGNIFICANCE 

There are now three types of box tests made at the For- 
est Products Laboratory: (1) drum, (2) drop, and (3) com- 

^See page 43. 

87 



irOODEN BOX AND CRATE CONSTRUCTION 




Fig. 23— Testing boxes in small revolving drum developed at Forest 
Products Laboratory. 



BOX AND CRATE TESTING 89 



•w,. 24 — Standard large drum testing machine developed at Forest 
Products Laboratory. 



90 WOODEN BOX AND CRATE CONSTRUCTION 




1 



Fig. 25 — Method of making drop-cornerwise test 
A. Releasing device, or trip. B. Cast iron plate. 



BOX AND CRATE TESTING 91 

pression. Drop tests may be made cornerwise or edgewise 
of the box ; compression tests are made on the edges, corners, 
or faces. In general, all these tests lead to the same conclu- 
sions ; the one selected in any particular case, however, will 
depend on the hazards to which the containers under consid- 
eration are subjected in transit. 

Drum Test 

The revolving drum type of box testing machine illus- 
trated in figures 23 and 24 is an approved and very practical 
method of testing boxes and crates. A vertical section of the 
drum at right angles to the axis is hexagonal in shape, which 
gives it six faces. Upon these six faces, hazards and guides are 
arranged in such a manner that, as the drum revolves, the box 
or crate slides and falls striking on ends, sides, top, bottom, 
edges, and corners in such ways that the stresses, shocks, and 
rough handling of actual transportation conditions are simu- 
lated. For this method of testing the box or crate must be 
loaded with its contents or a substitute which produces the 
same effect. 

The six faces, cleats, and edges of a box, numbered 
for testing in a revolving drum are shown in figures 3 and 4, 
Plate XIV ; and the corners of a crate and other parts as num- 
bered are shown by figures 1 and 2, Plate XIV. This number- 
ing is necessary in order that a record of the locations and 
character of the failures may be made as they occur. As the 
box moves on from one drop to the next, the observer notes 
the beginning of any failure, and he follows the progress of 
that and any other failure until the box becomes unserv- 
iceable. 

The weak feature of the box may be too few nails, nails 
of too short length, nails driven in a crack and thus having 
no great holding power, or some other form of nail weakness 
which the tests will clearly show. The material in the sides, 
top, or bottom may be too thin, so that the shocks of the 
falls pull the wood from the nails ; the wood may split or 
break across the grain. 

Any one of the numerous weaknesses of packing box 
construction may be demonstrated in this test, which enables 
the observer to design a box about equally serviceable in 
every feature, or balanced in construction. Such boxes will 
show failures equally likely to occur in nails pulling from 
the wood, wood pulling from the nails, splitting or breaking 



92 WOODEN BOX AND CRATE CONS-TRUCTION 

of ends, sides, tops or bottoms, and through the weaknesses 
of the wood species. 

Drop Tests 

Drop-Cornerwise Test — In the drop-cornerwise test, a box 
or crate with its contents is suspended by each of its corners 
alternately and dropped from a definite height upon a cast iron 
plate or other solid surface, as illustrated in figure 25. This is 
a very good test for comparing the strength of various types 
as regards their ability to resist this particular hazard of sud- 
den shock and distortive action. The test is very severe, how- 
ever, and several failures are apt to occur simultaneously, so 
that the test is not as good as the drum test for drawing con- 
clusions as to improvements of the design. 

In the drop test the corners of the box or crate where the 
various faces meet should be numbered as follows : 

Faces Corner 

meeting No. 

5-1-2 1 . 

6-3-4 2 

5-2-3 3 

6-1-4 4 

5-3-4 ■ 5 

■ 6-1-2 6 

5-1-4 7 

6-2-3 8 

The box or crate should then be dropped on the corners 
in numerical rotation and then the cycle repeated until failure 
occurs. The height of the drop is usually increased for each 
repetition of the cycle. 

Drop-Edgewise Test — The drop-edgewise test is similar 
to the drop-cornerwise test except that the container is 
dropped on an edge instead of a corner, being suspended from 
the diagonally opposite edge. 

Compression Tests 

Compression-On-An-Edge Test — In the test illustrated 
by figure 26, a compressive force is exerted over the whole 
length of one edge of a box and at right angles to it, the direc- 
tion of the force also passing through the diagonally opposite 
edge. This test measures the ability of a box or crate to resist 
being collapsed in this particular manner by external forces, 
enables comparisons to be made of the relative resistance in 
containers of the same design, and provides an additional 
method of comparing the strength of containers of different 



1 




in)X .IXJ) C RAT 11 TESTING 



93 




Fig. 26— Method of making comprcssion-on-an-cdge test. 



94 



WOODEN BOX AND CRATE CONSTRUCTION 




Fig. 27— Method of making compression-cornerwise test. 



BOX A.\m CRATE TESTING 



95 




Pig. 28 — Method of making compression-on-faccs test. 



96 WOODEN BOX AND CRATE CONSTRUCTION 

designs. This test is usually applied to the empty box or crate, 
although it may 'be applied to the container as packed for 
shipment. 

Compression-Cornerwise Test — Another compression test, 
figure 27, is conducted by applying compressive forces to two 
corners of a box or crate and directly along the line passing 
diagonally through those corners and the center of the box or 
crate. The general purposes of such a test are similar to those 
given for the preceding test, although it has the advantage of 
more readily determining the w^eakest elements of the con- 
struction. Each of these tests, however, brings out certain 
strength factors which the other does not, so that one can not 
be substituted for the other. 

Compression-On-Faces Test — A test which subjects a 
box or crate to the stresses that it encounters when support- 
ing heavy static loads in storage warehouses is obtained by 
direct compression at right angles to any two parallel faces, 
as illustrated in figure 28. • 

Supplementary Tests 

In addition to tests on completed boxes and crates there 
are many tests that will give much information of value to 
the designer, manufacturer, and user of boxes. Among these 
tests are the following : 

1. Mechanical-properties tests on sawed lumber, rotary- 
cut lumber, and plywood. (See page 26.) 

2. Holding power of nails, screws, bolts, and other 
fastenings. 

3. Tensile strength tests on metal strapping and wire 
ties and various methods of fastening them. 

4. Density determinations for woods to identify weak 
and brash stock. 

5. Determinations of the percentage of moisture in wood. 

6. Strength tests on glued joints. 

7. Tests on the strengthening effects of corrugated 
fasteners. 

8. Tests on special materials and details, such as rope, 
webbing and metal handles, hinges, hoops, locks, etc. 

As new designs of containers and their various accesso- 
ries are developed, corresponding tests will be necessary to 
determine their strength and advantages as compared to other 
containers and devices of a similar character. 



CHAPTER V 
BOX AND CRATE SPECIFICATIONS 

Standardization of Packing P>oxes — National Association 
OF Box Manufacturers' Tentative General Specifica- 
tions FOR Nailed and Lock Corner Boxes — Specific 
Specifications for' Nailed and Lock Corner Boxes — 
General Specifications for 4-One and Similar Boxes. 

Purpose— The purpose of box or crate specifications is to 
provide that part of a contract or agreement usually made be- 
tween a box manufacturer and his customer or other con- 
tracting parties which sets forth all of the details pertaining 
to the materials used and the construction of the container 
as they are to be furnished or executed by the manufacturer. 
The statements in a specification should be definite, concise, 
and clear. 

The specifications for a box or crate, so far as they afifect 
its actual strength, should only be such as will enable the 
container to perform satisfactory service. To require more 
than this will usually make the containers less economical. 

General specifications for wooden boxes nailed and lock 
corner are given below. They are divided into four parts, 
viz., material, grouping of woods, dimensions of parts, and 
manufacture. 

These general specifications are intended to serve as 
master specifications or standards of construction for nailed 
and lock-corner boxes. It is expected that specifications for 
boxes for a specific commodity or group of commodities will, 
as they are worked out through careful research, be made to 
conform closely to these general specifications, and that many 
of their requirements will be specified by reference to the 
general specifications. It will be necessary to add only such 
items as style and dimensions of box and minimum thicknesses 
of parts, and to enumerate such exceptions to the general 
specifications as may be found necessary. Many points must 
of necessity be common to all boxes of the classes under con- 
sideration, and brevity is gained by the scheme of specifying 

97 



98 WOODEN BOX AND CRATE CONSTRUCTION 

these in standards for boxes for a specific commodity by 
reference. 

The general specifications have the further value of pro- 
viding a much needed standard as a guide to the construction 
of wooden boxes. The principal features of these specifica- 
tions have been worked out from a large number of careful 
tests of boxes as such, and from very extensive data on the 
mechanical properties of woods as determined by the Forest 
Products Laboratory. 

STANDARDIZATION OF PACKING BOXES 

Paper Presented to National Association of Box Manufac- 
turers in Convention, April, 1920 

"Standardization of packing boxes for any commodity, like 
standardization of other products, tends to increase produc- 
tion, to insure uniform quality and to lower costs. This ap- 
plies not only to uniformity of dimensions of the box and its 
parts, but more especially to all those specifications of quality 
which directly affect the strength properties of the package. 

"Processes of standardization require system and order 
first of all. Haphazard assembling and grouping of essential 
specifications lead to duplications, errors, and omissions and 
tend to destroy the effectiveness of the work. No attempt 
will be made to complete this project before distributing the 
work. Instead, the general specifications and probably sev- 
eral chapters of detailed specifications will be distributed as 
compiled ; succeeding chapters to follow as they are com- 
pleted. It is advisable that those who receive these various 
installments should maintain a file for them. 

"This project of standardization for nailed and lock corner 
wooden boxes is based on a definite, systematic program, 
which will set forth, logically, concisely and completely, the 
best that can be compiled by this association, from its prac- 
tical experience, combining with this all that has been de- 
veloped in the scientific studies by trained engineers in the 
laboratory. 

"As in all other types or kinds of packing boxes, certain 
fundamental specifications are common to all nailed and lock 
corner wooden boxes. It is right and proper that these funda- 
mentals be stated as the first chapter in this work of standard- 
ization. In each succeeding chapter, which deals with the 
detailed specifications that apply to its particular group of 



BOX AND CRATE SPECIFICATIONS 99 

boxes, reference will be made to the general specifications 
only when an exception is to be made in the interest of 
greater efficiency or lower costs of production. 

"Each chapter or bulletin will be devoted to the boxes in 
common use for one general class of commodities, giving the 
specific thicknesses of material to be used for those particular 
boxes, and where practicable preferential sizes, together with 
such comments and notations as may be desirable in the in- 
terest of proper packing. 

"In compiling these specifications, acknowledgment is 
made for the careful and comi)rehensive work of the U. S. 
Forest Products Laboratory, Madison, Wis., and for the co- 
operation of those leaders in the box making industry whose 
experience has been drawn upon to make these specifications 
thoroughly practicable. The continued work of research will 
produce new and greater economies, this, with changing man- 
ufacturing and commercial conditions, will necessitate fre- 
quent changes in standardized box construction and in 
specifications. 

"To those associations of shippers and to those in trans- 
portation lines, whose activities require them to compile 
standard of box construction, whether for wooden boxes or 
for any of the other types or kinds of containers, this method 
of compiling, (1) the general specifications and (2) the de- 
tailed specifications, is recommended as absolutely necessary 
if clear, concise, comprehensive, efficient and economical re- 
sults are to be obtained. 

NATIONAL ASSOCIATION OF BOX MANUFACTURERS' 

TENTATIVE GENERAL SPECIFICATIONS FOR 

NAILED AND LOCK CORNER BOXES' 

A. Material 

Material — The ends, sides, tops, bottoms and other parts 
of wooden boxes must be well manufactured and be cut true 
to size. All defects in the lumber that materially lessen the 
strength of the part, expose contents to damage, or niterfere 
with proper nailing, must be eliminated. The lumber must 
be thoroughly seasoned, viz., have an average moisture con- 
tent of 12 to 18 per cent, based on the weight of the wood 
after oven drying to a constant weight. 



'Adopted as tentative general specifications for nailed and lock corner boxes 
by the American Society of Testing Materials. 



ICO 



WOODEN BOX AND CRATE CONSTRUCTION 



B. Grouping of Woods 

Grouping of Woods — The principal woods used for boxes 
are classed for the purpose of specifications in four groups : 



Group I 



White pine 

Norway pine 

Aspen (popple) 

Spruce 

Western (yellow) pine 

Cottonwood 

Yellow poplar 

Balsam fir 

Chestnut 

Sugar pine 

Cypress 

Basswood 



Willow 
Noble fir 
Magnolia 
Buckeye 
White fir 
Cedar 
Redwood 
Butternut 
Cucumber 
Alpine fir 
Lodgepole pine 
Jack pine 



If 



Group II 

Southern yellow pine Douglas fir 

Hemlock Larch (tamarack) 

North Carolina pine 

Group III 

White elm Black ash 

Red gum Black gum 

Sycamore Tupelo 

Pumpkin ash Maple, soft or silver 



Group IV 



Hard maple 
Beech 
Oak 
Hackberry 



Birch 
Rock elm 
White ash 
Hickory 

C. Thickness of Lumber 



Thickness of Parts — The thicknesses called for in specifica- 
tions for boxes of any given commodity will, unless otherwise 
stated, be understood as applying to Groups I and II woods. 
Where the material is specified (for Groups I and II woods) 
as not more than ^ inch thick and not less than j's irch, 
Groups III and IV woods may be used ^V iT^ch less in thick- 
ness ; where the material is specified (for Groups I and II 



I 



BOX AND CRATE SPECIFICATIONS 101 

woods) as more than ^A inch thick and not more than 1 inch, 
Groups III and IV woods may be used ]4> inch less in thick- 
ness ; where the material is specified (for Groups I and II 
woods) as more than 1 inch thick and n6t more than 2 inches, 
Groups III and TV woods may be used ^ inch less in 
thickness. 

The thickness of lumber specified allows for an occa- 
sional unavoidable variation, but that variation shall not ex- 
ceed one-eighth of the. thickness of the part below the thick- 
ness specified. 

D. Widths of Material 

Widths of Parts — The maximum number of pieces allowed 
in any side, top, bottom, or end of a box shall be as follows: 

Width of face Maximum number of pieces 

5 inches or under 1 

Over 5 or under 8 inches, inclusive 2 

" 8 " " 12 " " 3 

" 12 " " 20 " " 4 

For each additional 5 inches in width of face, one addi- 
tional piece may be used. No piece less than 2i/2 inches face 
width at either end may be used in any part, except for cleats 
or battens. 

E. Surfacing 

Surfacing — The outside surfaces of boxes must be suffi- 
ciently smooth to permit of legible marking. 

F. Joining 

Joining — Ends 1 inch or less in thickness, if made of two 
or more pieces, must be either butt-jointed or matched, then 
fastened with two or more corrugated fasteners or must be 
cleated. For ends %, -jf, and ^ inch thick, use fasteners 1 
by y^ inch ; for ends ^ inch thick, use fasteners 1 by ^ inch ; 
for ends ^ and -j'Vi inch thick, use fasteners 1 by Y^ inch. Two 
or more pieces Linderman jointed shall be considered as one 
piece. 

G. Schedule of Nailing 

Size of Nails — All nails specified are standard cement 
coated box nails. (If other than cement coated nails are used 
25 per cent more nails must be driven than specified). Plain 
nails driven through and clinched may be used for cleating. 



102 



WOODEN BOX AND CRATE CONSTRUCTION 



The size of the nail to be used shall be governed by the species 
and thickness of the material in which the points of the nails 
are held. If the designated penny of nail is not available, use 
the next lower penny and space nails proportionately closer. 
Nails should be driven flush — overdriving materially weakens 
the container. 

Nailing Schedule 



Use cement coated 

nails of size 

indicated when 

species of wood 

holding nails is 



Group I woods 
Group II woods 
GroupIII woods 
Group IV woods 



Thickness of ends or cleats to which sides, 
tops and bottoms are nailed 



3/8 
or 
less 



4d 
4d 
3d 
3d 



7/16 



5d 
4d 
4d 
3d 



1/2 



5d 
5d 

4d 
4d 



9/16 



6d 
5d 
5d 
4d 



5/8 



7d 
6d 
5d 
4d 



11/16 
or 
3/4 



8d 
7d 
6d 
5d 



13/16 



8d 
7d 

7d 
6d 



7/8 



9d 

8d 
7d 
7d 



Thickness of sides 
to which top and 
bottom are nailed 



Less 
Than 

1/2 



4d 
4d 
3d 
3d 



1/2 


5/8 


to 


to 


9/16 


7/8 


6d 


7d 


5d 


6d 


4d 


5d 


4d 


5d 



H. Spacing of Nails 

Spacing of Nails — In order to ascertain the number of 
nails to be used, divide the width of the side, top and bottom 
(or length of cleat) by the spacing specified for the g^auge of 
nails to be used. Fractions in the result greater than ^ (if 
the points of nails are to be held in the end grain) and greater 
than ^ (if the points of nails are to be held in the side grain) 
will be considered as a whole number. 

Space when driven into 
When nails are Side grain of end End grain of ©nd 

6d or less 2 inches 1^ inches 

7d 254 " 2 

8d 2^ " 2^ " 

9d 2^ " 2y2 " 

lOd 3 " 2^ " 

No board shall have less than two nails at each nailing 
end. Where cleats of thickness not less than the thickness of 
the ends are used, approximately 50 per cent of the nails will 
be driven into the cleats. 

Space nails holding top and bottom to sides six to eight 
inches apart. (When material in sides is less than j/2 inch 
thick, do not side nail unless otherwise specified.) 



BOX AND CRATE SPRCIPICATIONS 



103 



SPECIFIC SPECIFICATIONS FOR NAILED AND LOCK 
CORNER BOXES' 

The following are specifications for Nailed and Lock 
Corner boxes for carrying specific commodities, minimum 
thickness of lumber and maximum gross weights : 

Canned Food Cases 



Commodity 


Type of 
box 
construc- 
tion 


Minimum thickness of the 
material expressed in frac- 
tions of an inch, woods of 
Groups I and II. (See Gen- 
eral specifications for com- 
parative thicknesses of 
woods in Groups III and IV) 


Maxi- 
mum 
gross 
weight 
of box 
and 
contents 


For excep- 
tions to gen- 
eral specifi- 
cations see 
reference to 
notes as 

numbered 




Ends 


Sides 


Top and 
bottom 


Canned foods in 
metal cans, viz.: 
fish, fruits, meats, 
milk, vegetables, 
other foods 


Nailed.. 


5/8 
5/8 


5/16 

3/8 


5/16 

3/8 


90 
125 


Notes 1, 2 
Notes 1,2, 3 


Lock- 
corner . 


7/16 

1/2 
5/8 


7/16 
5/16 
5/16 


5/16 
5/16 
5/16 


50 
50 
90 


Notes 1, 2 
Notes 1, 2 
Notes 1, 2 



Notes and Exceptions 

Note I — When one-piece sides and two-piece tops and 
bottoms of Groups I and II woods are used, material 'may be 
nV inch thinner than specified. When rotary cut gum lumber 
is used, with one-piece sides and tops and not more than two- 
piece bottom, the thickness may be -j^ inch less than speci- 
fied for Group III woods, minimum thickness ^4 inch. 

Note 2 — Inside dimensions of boxes shall not exceed V^ 
inch over exact length and width and Y^ inch over exact 
depth of contents. 

Note J — Ends must be cleated. 

GENERAL SPECIFICATIONS FOR 4-ONE AND SIMILAR 

BOXES 

The following specifications are substantially those 
adopted as general specifications by the 4-One Association 
of Box Manufacturers, and as tentative general specifications 
by the American Societv for Testing Materials. 



'The foregoing general specifications would be incomplete without an illustra- 
tion of their application to a specific commodity. Therefore, specific specifications 
for canned food containers, as adopted bjf the National Association of Box Manu- 
facturers, are set forth. Specifications for boxes for other commodities have been 
adopted, but will not be incorporated in this book. 



104 



WOODEN BOX AND CRATE CONSTRUCTION 



Material Covered 

1. These specifications cover three, styles of 4-One and 
similar type boxes as follows : 

(a) General form. 

(b) Boxes with wedgelock ends. 

(c) Boxes with detached tops. 

2. General Form — (a) The boxes knocked down shall 
consist of four separate sections forming" top, side, bottom, 
side, connected only by continuous steel binding wires; and 
of separate ends. 

(b) Each of the separate sections forming the sides, 
top, and bottom shall consist of cleats, thin boards, wires, 
and staples. 

(c) The four sections shall be separated such a dis- 
tance from each other that the wires shall be in tension at 
the corners when the sections are folded. 

3. Grouping of Woods — For the purposes of these 
specifications, box lumber shall be classed into four groups 
as follows : 



Alpin fir 
Aspen (popple) 
Balsam fir 
Basswood 
Buckeye 
Butternut 
Cedar 
Chestnut 



Group I. 

Cottonwood 
Cucumber 
Cypress 
Jack pine 
Lodgepole pine 
Magnolia 
Noble fir 
Norway pine 



Redwood 

Spruce 

Sugar pine 

Western yellow pine 

White fir 

White pine 

Willow 

Yellow poplar 



Douglas fir 

Hemlock 

Larch 

(tamarack) 



Group II. 

Southern yellow 
pine 



Group III. 



Virginia and 
Carolina pine 



Black ash Red gum Sycamore 

Black gum Red gum sapwood Tupelo 

Maple, soft or silver (commonly White elm 
Pumpkin ash called sap gum) 



BOX AND CRATE SPECIFICATIONS 105 

Group IV. 

Beech Hickory Rock elm 

Birch Maple, hard White ash 

Plackberry Oak 

Materials 

4. Cleats — (a) Each cleat shall be sound, free from 
knots and from cross grain which runs across it within a 
distance equal to one-half its length. 

(b) Cleats shall be not less than ^/\ inch thick (paral- 
lel to the length of the box) and not less than J-g inch in 
width. 

5. Thin Boards — (a) The thin boards shall be sound 
(free from decay and dote), well seasoned and cut so that ad- 
jacent faces of boxes will be at right angles to each other. 
All defects that would materially lessen the strength, expose 
the contents of the boxes to damage, or interfere with the 
proper assembly of the boxes shall be eliminated. 

(b) When the thickness of thin boards as specified is 
less than -f^ inch, thin boards made of woods of Groups III 
and IV may be g^ inch less than the specified thickness ex- 
cept that the minimum thickness of thin boards of any kind of 
wood shall be ]4, inch. 

(c) The variation in thickness of thin boards below the 
thickness specified shall be not more than \4, of the thickness 
of the thin board, and this variation below the specified 
thickness shall not extend to more than 10 per cent of the 
face of that particular board, 

(d) Thin boards less than 2^ inches in width at either 
end shall not be used. 

6. Staples— The binding wires shall be annealed steel 
wire of not less than No. 16 gauge. 

7. (a) The staples on end wires shall be not less than 
No. 16 gauge by 1^ inches long. 

(b) Staples on intermediate wires shall be nc^t less than 
No. 18 gauge by yV irich long. 

Assembling 

8. (a) The staples on end wires shall be driven home 
astride the binding wires, through the thin boards into the 
cleats, and anchored in the cleats. 

(b) The staples on the intermediate wires shall be 



106 Jl'OODEN BOX AND CRATE CONSTRUCTION 

driven astride the binding wires, through the thin boards 
and firmly clinched. 

(c) The space between staples shall be the average dis- 
tance between centers of staple's astride each binding wire 
in each section and this space shall be not more than 2^2 
inches except as specified in paragraph (d). 

(d) When cleats are made of woods of Groups III and 
IV the space between the staples may be J4 inch greater 
than that specified. 

(e) There shall be not less than two staples driven 
astride each wire and into each thin board. 

(f) The staples nearest the corners shall be not more 
than 1^ inches from the corner to which it is adjacent. 

9. Each end of the box shall be securely fastened on the 
inside of the side cleats with staples not less than N-O. 16 
gauge by yf inch long, or with cement-coated nails of not 
less than two-penny size. There shall be no space exceeding 
2^ inches on any side cleat into which no staple or nail hold- 
ing the end in place has been driven and there shall be a 
staple or nail within 1^ inches of each end of each side cleat. 
Staples or nails shall be driven home. 

10. At each corner one section shall overlap its adjacent 
section at right angles and the wire shall be in tension, giv- 
ing a square, tight corner. 

11. The cover shall be closed tightly and the ends of 
each binding wire twisted tightly together. The twisted 
portion of each wire shall be not less than lA inch long. The 
rough ends of the wires shall be removed and the twisted 
portion driven flat against the side parallel with the binding 
wire. 

12. Nothing herein contained shall be construed as pro- 
hibiting the use of boxes constructed of thicker thin boards, 
additional or heavier wires, heavier cleats, longer staples, 
or with closer spacing of staples. 

13. Boxes with Wedgelock Ends — These boxes shall 
consist of sides, top, and bottom and one end made in ac- 
cordance with sections 2-12 inclusive, pages 104 to 106, inclu- 
sive, and of one wedgelock end. 

14. Wedgelock ends shall consist of the following: 

(a) One or more thin boards whose thickness is not less 
than that of the thin boards in the other portions of the box 
and whose combined width is }i inch less than the shortest 
distance between the top and bottom cleats of the box and 



nOX AND CRATIi SPIiCl mCAI'lONS 107 

whose length is the same as the inside width of the box less 
the width of one of the side cleats. 

(b) Two battens of the same thickness and width as 
the cleats in the box and wht)se length is j/8 inch less than the 
shortest distance between the top and bottom cleats. 

(c) One wedge of the same thickness and length as 
the battens and whose width is one-half that of the battens. 

15. The battens shall be attached across the grain of the 
thin boards, one batten its own width from one end and the 
other batten half its width from the other end of the thin 
boards,, with staples not less than No. 16 gauge by \% inch 
long or with nails not less than two-penny size. There shall 
be no space exceeding 2 inches on any batten into which no 
staple or nail holding the thin boards to the batten has been 
driven and there shall be a staple or nail within lyi inches of 
each end of each batten. Staples or nails shall be driven 
home. 

In making up the box, the wedgelock end is left out so 
that the box may be filled from the end. The other end of the 
box is fastened in place and the box made up as specified in 
sections 9-11, page 106. The wedgelock end is not fastened in 
place until the box is closed. 

Boxes with wedgelock ends are closed as follows : 
The wedgelock end is inserted. The wedge is inserted, 
the batten that rests against the wedge is fastened to the 
wedge with one four-penny nail driven through the middle 
of the batten into the wedge. The other batten that rests 
against the cleat is fastened to that cleat with four-penny 
nails driven through the batten into the cleat. Nail centers 
shall be not niore than 4 inches apart, and there shall be a 
nail within at least 2 inches of each end of this batten. 

16. Boxes with Detached Tops — These boxes shall con- 
sist of sides, bottom and ends made in accordance with sec- 
tions 2-12 inclusive, pages 104 to 106, and a detached top made 
of thin boards. 

17. In assembling the box, the top cleats to which the 
binding wires have been stapled shall be put in position on 
the side cleats and the ends of each wire stapled to the cleats 
twisted tightly together. 

The detached top shall be nailed to the end cleats with 
cement-coated box nails spaced not more than 23/2 inches 
apart. The wires not stapled to the cleats shall be brought 
over the detached top and the ends of each \\\m twisted 
tightly together. 



CHAPTER VI 

STRUCTURE AND IDENTIFICATION OF WOODS 

Structure of Wood — Procedure in Identifying Wood — Key 
FOR the Identification of Woods Used for Box and 
Crate Construction — Description of Box Wood — Grad- 
ing Rules for Rotary-Cut Lumber. 

More than forty different species of wood are used in 
box construction. It is essential to be able to distinguish 
these woods in order that they may be used intelligently. For 
instance, it is necessary to be able to classify the commercial 
woods used for boxes into the four groups outlined in the 
specifications for boxes and crates, (See grouped list, Part V, 
page 100.) Such properties as color, odor, taste and weight are 
very helpful in placing any given wood in the group where it 
belongs; information as to the section of the country from 
which the wood was obtained is also of assistance ; but some 
knowledge of structure is indispensable for accurately making 
the required distinctions. When a wood is dry it may lose 
much of the odor that distinguished it when green; if it is 
stained, weathered, or artificially treated, any characteristic 
color may not be apparent ; its weight, too, when it is green 
(saturated with moisture), when partly seasoned, and when 
kiln-dried is very dififerent; under all these conditions, how- 
ever, the structure is practically unchanged and, therefore, 
serves as an unfailing guide in identifying the wood. More- 
over, accurate descriptions of characteristic structures are 
possible, whereas descriptions of color and so-called "grain" 
are difficult to put into words and are open to wrong inter- 
pretation because of the variation of individual opinions and 
observations on "grain" and color. 

The identification of woods as described in the following 
pages, therefore, is based primarily on the structure of the 
wood, but is supplemented by such other physical properties 
as are helpful in distinguishing the different species or groups 
of woods. , 

108 



STRUCTURE AND IDENTIFICATION OF WOODS 109 

STRUCTURE OF WOOD 

Heartwood and Sapwood 

In mature trees two portions of the wood of the trunk 
are generally to be distinguished. These are the sapwood and 
the heartwood. The sapwood is found next to the bark ; it is 
generally light colored and varies only slightly in shade. It 
varies considerably, however, in width. In some species it is 
less than an inch wide, as, for example, in arborvitae, western 
red cedar, black ash, and slippery elm. On the other hand, in 
other species, such as maple, birch, hickory, white ash, green 
ash, hackberry, and some hard pines, it is several inches in 
width. Besides the variations in sapwood in species, the width 
of sapwood may also vary within the same tree or species, 
depending upon the age, vigor of growth, and height above 
the ground of the individual specimen. The sapwood con- 
tains living cells and it is through this portion of the woody 
cylinder that the sap circulates in the tree. 

The heartwood is dead so far as the life processes of the 
tree are concerned. The heartwood was once sapwood. After 
serving for sap conduction and other growth activities for a 
number of years the sapwood gradually, often without any 
sharp line of demarkation, changes into heartwood and ceases 
to function in the life of the tree except for the fact that it 
gives mechanical support to the crown, thus helping hold the 
leaves up in the sunlight. The change from sapwood to heart- 
wood is very often, but not always, accompanied by a change 
in color. Some woods in which the change in color is lack- 
ing or very slight are white and red spruce, hemlock. Port 
Orford cedar, basswood, white cottonwood, aspen or "popple," 
buckeye, "whiteheart" beech^, and hackberry. The color of 
the heartwood, when markedly different from that of the sap- 
wood, is of great assistance in identifying different species of 
wood, such as red gum, yellow poplar, and black ash. 

The structure of the sapwood and the heartwood is the 
same except for the fact that the pores or large tube-like cells 
of the heartwood of some hardwoods are frequently more or 
less closed with cell-like growths called tyloses or with 
gummy substances. In the sapwood, especially in the outer 
sapwood next the bark, the pores are open and serve to con- 
duct sap. Sometimes the sapwood of lumber becomes much 
discolored, blued, or darkened, through the presence of sap- 

'Some beech has a very reddish heartwood frequently with different properties 
from the "whiteheart" beech — this is often called "redheart" beech. 



no WOODEN BOX AND CRATE CONSTRUCTION 

stain fungi. Some woods in which the sapwood is often blued 
or otherwise stained are pines, spruces, red gum, and hack- 
berry. In hackberry the stained sapwood often appears darker 
in color than the heartwood. Discoloration may also be pro- 
duced by chemical changes in the wood without the action 
of fungi ; for example, brown stain in sugar pine or the colors 
produced by the contact of the saw with the substances in oak. 

Annual Rings 

Annual rings are the more or less well defined concentric 
layers of wood laid down each year by the growing tree. They 
are particularly noticeable on the stump of a tree or on any 
cross section of the wood. Annual rings are more conspicu-' 
ous in oak, elm, and ash, or pine and fir than they are in woods 
like "popple" or aspen, buckeye, cottonwood, tupelo, and wil- 
low. Many woods grown in the tropics do not show well 
defined annual rings, although they may show zones of growth 
due to changes, often not annual but produced by climatic 
conditions other than the summer and winter changes of tem- 
perate climates. 

The appearance of the annual rings on a smoothly-cut 
cross section is of great assistance in identifying woods. 

Springwood and Summerwood 

The springwood is that part of the annual ring which is 
first formed each year. The wood is usually lighter in weight 
and softer because it contains more air spaces, that is, larger 
cell cavities and less wood substance than that formed later 
on in the year. As the season advances the cell walls formed 
are usually thicker and the cavities smaller so that the growth 
which is called summerwood is denser, harder, and often 
darker in color than the springwood. In some woods, such as 
maple, birch, and basswood, there is a little difiference between 
the springwood and summerwood. In the case of spruce or 
hemlock the change from springwood to summerwood is grad- 
ual, but in oak and longleaf pine, for instance, the difiference 
between springwood and summerwood is not only marked 
but the change is very abrupt. It is often possible to estimate 
the strength of wood by noting the percentage and density of 
the summerwood, 



STRUCTURE AND IDENTIFICATION OF WOODS 111 




Fig. 29 — Section (>\ western yellow pine log showing: radial surface, R; 
tangential surface, T ; heartwood, H ; sapwood, S ; pith, P. The annual 
rings are the concentric layers widest near pith and usually Iieconiing nar- 
rower toward the hark. The summer wood produces the dark lines that 
stand out conspicuously on hoth the radial and tangential surfaces. 



112 WOODEN BOX AND CRATE CONSTRUCTION 

The Structure of Hardwoods 

The name "hardwood" applies chiefly to woods which are 
characteristically hard and strong, such as oak, hickory and 
ash. The hardwood group, however, includes some woods 
which are not relatively very hard, as, for instance, basswood 
and "popple." The real distinction on which the grouping 
into hardwoods and softwoods is based is not the hardness 
but the structure of the wood. 

All the commercial hardwoods of the United States con- 
tain pores or vessels, cells which are strikingly larger than the 
other cells with which they are associated. The conifers or 
softwoods do not have these pores or vessels. They are often 
called non-porous woods. Some of them, for example south- 
ern yellow pine or Douglas fir, may be actually harder than 
such hardwoods as basswood. The hardwoods, for the most 
part, come from broad-leaved trees, such as maple, elm, and 
poplar, and the softwoods from needle or scale-leaved trees 
like pines or cedars. 

All hardwoods have pores. In many cases pores are 
visible to the naked eye. They appear on a smoothly-cut 
cross section as more or less circular openings. On a longi- 
tudinal section they appear like fine, more or less interrupted 
grooves and may be used to determine the direction of the 
grain, as, for example, cross or spiral grain. Where they are 
not visible to the naked eye they may be seen with the aid of 
a magnifying glass with an enlarging power of about 12 to 18 
diameters. The group, however, may be divided into two 
classes according to the arrangement of these pores. When 
the large pores are grouped conspicuously at the beginning of 
each annual ring and there is an abrupt change in size from 
the springwood to the summerwood pores the woods are 
called ring-porous. The springwood pores are usually visible 
to the naked eye in this type of wood. Examples of ring- 
porous woods are oak, ash, elm, hickory, and locust. In this 
type of wood the annual rings are distinctly defined. 

If, on the other hand, the pores are scattered with con- 
siderable uniformity throughout" the ring and the change in 
the size of the pores from the inner to the outer portion 
(spring to the summerwood) is slight or gradual, the woods 
are called diffuse-porous. Examples of woods of this sort are 
maple, birch, tulip, gum, sycamore, and willow. 

Tyloses are cell-like growths which often appear like a 



STRUCTURE AND IDENTIFICATION OF WOODS 113 

froth or a number of glistening i)artick'S in the pores of the 
hardwoods. They are especially conspicuous in such woods 
as hickory and most of the white oaks. Tyloses, when pres- 
ent, are found in the inner sapwood and the heartwood. The 
outer sapwood pores are normally open. The presence of 
tyloses is often of assistance in identifying- woods. White 
oak with an abundance of tyloses, for instance, is used for 
tight cooperage (barrels to contain liquids), while red oak, 
which generally (not always) lacks tyloses, is not as suitable 
for liquid containers and is used for slack cooperage (barrels 
for dry materials such as cement or flour). 

Lines of light colored tissue extending out from the pores 
may be seen on the smoothly-cut cross section of such woods 
as white, green, or pumpkin ash. These lines are of consider- 
able assistance in identifying these woods. They are com- 
posed of small rather thin-walled cells which may easily be 
crushed when a section is cut. These cells are known as 
parenchyma tissue. 

Rays (often called medullary rays) are more or less nar- 
row strips of cells which extend from the bark towards the 
center of the tree. They run horizontally at right angles to 
the vertical grain of the wood. They may be compared to 
minute two-edged swords thrust from the inner bark toward 
the heart of the tree. On the end surface they appear as lines, 
crossing the annual rings, like the radii of a circle or the 
spokes of a wheel, although all the rays do not originate at 
the center of the tree. The rays are very large and conspicu- 
ous in oaks, in which they are sometimes said to produce 
"silver grain" or "fleck." The rays are also easily seen .with 
the naked eye in sycamore and beech. Although they are 
visible in all woods on truly radial surfaces, especially on 
split surfaces, and in many woods on the end surface there 
are also a considerable number of species in which they can- 
not be seen on the end surface with the naked eye. Quarter- 
sawed or edge-grain material is produced by cutting through 
the center of the tree approximately parallel to these rays 
(radial cut). Flat-grained, slab, or plain-sawed material is 
cut at right angles to the rays (tangential cut). 

Wood fibers are the small cells which make up the greater 
part of the dense wood substance between the pores and the 
rays of hardwoods. They are thick-walled and too small to 
be seen individually without considerable magnification. Col- 



114 WOODEN BOX AND CRATE CONSTRUCTION 

lectively, they are seen to form the darker, denser portions 
which give most of the weight and strength to the wood. 

Pith flecks are small dark spots or streaks which occur 
characteristically in certain woods, as, for example, soft maple 
and river birch. 

The Structure of Conifers 

In conifers or softwoods the rays and the fiber-like cells 
(tracheids) make up the wood. The tracheids serve the com- 
bined purpose of the pores and the wood fibers of the hard- 
woods, that is, they support the tree and assist in the con- 
duction of the sap. The truth of the statement that wood 
resembles a honeycomb is strikingly evident when the struc- 
ture of a softwood is examined under a lens. In the wood the 
cells are, in proportion to their width, longer than they are 
in the honeycomb, although they are rarely over ^ inch in 
length. The resemblance is due to the regularity of arrange- 
ment of the cells, which are of approximately uniform width 
tangentially and are arranged in very regular radial rows, as 
is apparent in the pictures of conifer cross sections. (See 
figure 2, Plate II.) Because the conifers do not have 
cells which are strikingly larger than the other cells (pores) 
they are called non-porous woods or woods without pores. 
(It should be noted that the word "porous" as applied to sub- 
stances like a sponge, which contain empty spaces and may 
absorb liquids, may be applied also to both softwoods and 
hardwoods which, of course, contain air spaces ; but the word 
"pore" or "vessel" is used in the classification of hardwoods 
and conifers in a dififerent sense when reference is made to 
the presence of a definite type of cell in the hardwoods or 
"porous" woods.) 

In the softwoods the annual rings are usually very clearly 
defined (more clearly than in some diffuse-porous woods) 
because toward the close of the growing season the cells be- 
come thicker walled and are flattened somewhat radially, thus 
producing the distinctive summerwood of the annual rings. 

The rays in the conifers, although present, are so small 
as to be invisible on the end surface without a lens. They 
are very numerous, however, as many as fifteen thousand to 
the square inch (21 to 27 per square mm.) of tangential sur- 
face have been noted in such a wood as pine.^ 

^U. S. Department of Agriculture, Division of Forestry, Bulletin 13. The 
Timber Pines of the Southern U. S., page 152. 



STRUCTURE AND IDENTIFICATION OF WOODS 115 

Resin passages or ducts are found in four genera of the 
conifers, namely, in pines, spruces, Douglas fir, and larch or 
tamarack. Resin ducts are openings which have been pro- 
duced when the cells of the wood have split apart, that is, 
they are intercellular spaces. These passages or ducts extend 
both vertically and horizontally in the tree. The vertical 
ducts in the woods mentioned usually occur in or near the 
summerwood and are more visible than the horizontal ducts 
which are found in some of the rays (fusiform rays). These 
latter may be seen as very minute dark specks on the tan- 
gential surface of the woods of the species just mentioned. 
Resin is stored in these ducts or intercellular spaces and often 
gives them a brownish or amber color which assists in their 
detection, especially on longitudinal surfaces. The ducts, 
especially the vertical ones, are most conspicuous in pines. 
When a very smoothly-cut end-grain surface is examined the 
vertical resin ducts are barely visible to the naked eye as 
minute dots in or near the summerwood. In spruces, larches, 
and Douglas fir the resin ducts are usually smaller and less 
numerous than in pines, and they are sometimes found in 
short tangential rows. The direction of the grain, especially 
spiral grain, may be determined by observing the vertical 
resin ducts which run parallel with the fibers. Exudation of 
resin sometimes occurs from the ducts on the ends of pieces 
of these four kinds of woods. The absence of such exuda- 
tions of resin does not necessarily mean that resin ducts are 
not present, for, as a rule, the resin does not exude from the 
ducts in seasoned wood unless the wood is heated. In woods 
in which resin ducts are present pitch pockets or pitch streaks 
may also be found. Such coniferous woods as cedars, cypress, 
redwood, and balsam firs do not normally have resin ducts. 
They may, however, contain some resinous material in their 
rays or in certain scattered cells. 

PROCEDURE IN IDENTIFYING WOOD 

If color, odor, weight, or general appearance is not suffi- 
ciently distinctive to identify a specimen of wood, an examina- 
tion of the more detailed structure should be made. In the 
key which follows, the somewhat similar woods are syste- 
matically grouped together and the characteristic distinctions 
by which they can be separated are given to assist in rapid 
and accurate identification. Photographs showing a slightly 



116 WOODEN BOX AND CRATE CONSTRUCTION 

magnified cross section of the dififerent species are also given. 
These show very clearly the distinctions which may usually 
also be seen with the naked eye on a smoothly-cut surface of 
the end grain of the wood. Contrary to common practice, 
it is the cross section or end grain, which, when smoothed off, 
with a very sharp knife, usually presents the best surface 
from which to make an identification ; for, in general, it is 
here rather than on the longitudinal surface that the prin- 
cipal distinctive characteristics in a difficult identification are 
to be found. The need of a very sharp knife and smoothly- 
cut surface cannot be too strongly emphasized. With a dull 
knife scratches and other irregularities may be produced 
which are sometimes mistaken for structures. 

To determine the color of a wood a freshly-cut longi- 
tudinal surface of the heartwood should be used, since ex- 
posed surfaces may become weathered or soiled so that the 
characteristic color is changed. Odor and taste should also 
be determined from freshly-cut surfaces, shavings, or saw- 
dust, since they are often lost if the material is exposed to the 
air for any length of time. 

The first step in identifying an unknown wood is to de- 
termine whether or not pores are present. In many woods 
the pores are readily visible to the naked eye, but in some 
they are difficult to see or invisible without magnification. 
This is particularly true in certain dififuse-porous woods, such 
as sycamore, beech, red gum, maple, yellow poplar, basswood, 
tupelo, buckeye and aspen. In the case of practically all of 
these woods, however, there are characteristics which readily 
distinguish them from the somewhat similar appearing soft- 
woods where pores are lacking. These are, for instance, the 
relatively large rays found in beech, sycamore, maple, and 
basswood, the color of the heartwood of red gum and yellow 
poplar, and the lack of sharply-defined annual rings in tupelo, 
aspen, and buckeye, together with other details which a^e 
given in the key, thus making it possible readily to separate 
these hardwoods from certain of the softwoods for which they 
might be mistaken. 

After determining whether a wood is a hardwood (with 
pores) or a softwood (without pores), the next step is to 
place the wood under one of the sub-divisions under the group 
to which it belongs ; that is, if it is a hardwood, note whether 
it is ring-porous or diffuse-porous. Then if it is a ring-porous 
wood, note whether or not the summerwood is figured and. 



STRUCTURE AND IDENTIFICATION OF WOODS 117 

if so, whether the figure of the summerwood runs with the 
rays across the rings (radial) figures 1, 2, and 3, Plate XVI, 
or with the rings (tangential), figures 4, 5, 6, 7, and 8, Plate 
XVI. 

The most distinctive features within the diffuse-porous 
group are the size of the pores and the size of the rays, the 
color and the weight of the wood. 

If, on the other hand, the wood is a conifer (without 
pores), the annual rings are usually well defined by the con- 
trast between springwood and summerwood. The principal 
characteristics in this group are odor, presence of resin ducts 
in certain woods, color, and weight. 

It is not to be expected that the key can be used success- 
fully without some practice. It is also very desirable that 
the person who is to make a specialty of wood identification 
should have a collection of known samples of wood which 
show characteristic color and structure (that is, not extremely 
fast or extremely slow growth) for comparison. It should be 
noted that in the key the name of the wood follows its 
description. 



KEY FOR THE IDENTIFICATION OF WOODS USED 

FOR BOX AND CRATE CONSTRUCTION^ 

(without the aid of hand lens) 

Hardwoods 

Woods from broad-leaved trees. 

Woods with pores or vessels, that is, cells larger than 
those surrounding them. 

I. Pores present — (Sometimes not visible to the naked eye 
in certain diffuse-porous woods, in which, however, the 
distinct rays or lack of well-defined summerwood dis- 
tinguish them from conifers.) 
/I. King-porous zwods — The comparatively large spring- 
wood pores are clearly visible, especially in the 
sapwood at the beginning of each annual ring. On 
the end grain of a log these pores form distinct 
rings. The marked difference between springwood 



•Unless otherwise stated all observations of structure are made on a smoothly 
cut cross section or end (rrain showing prrowth rings of average width. A sharp 
knife is indispensable. All color delermination should be made on a freshly-cut 
longitudinal surface of the heartwood. See pages 126 to 136 for a more detailed 
discussion of each wood. 



118 WOODEN BOX AND CRATE CONSTRUCTION 

and summerwood is characteristic. Longitudinal 
surfaces appear coarse textured because of the 
large springwood pores which show as fine grooves 
or furrows, often producing a characteristic figure. 
These woods are mostly heavy and are found in 
box wood groups three and four. Chestnut, which 
is a ring-porous wood, is an exception ; it is fairly 
light when seasoned and is classified in group one 
of the box classification. 

1. Summerwood figured with wavy or branched radial bands. 

(Bands extend across the rings in the same direction as 
the rays.) 

(Compare Plate XVI, figures 1 to 3.) 
AA. Rays, many, broad, and conspicuous. They appear 
as "flecks" or "silver grain" on quarter-sawed mate- 
rial. Wood heavy to very heavy. Sapwood rather 
narrow. 40-49\ THE OAKS. 4^. 

BB. Rays not noticeable. Color grayish brown, texture 
coarse. Sapwood narrow. Wood moderately light. 
30. CHESTNUT. 1 

2. Summerwood figured with short or wavy tangential lines 

(running more or less parallel with the rings), often 
most noticeable toward the outer part of the growth 
ring. (Compare Plate XVI, figures 4 to 8.) 
AA. Heartwood not distinctly darker than sapwood (sap- 
wood sometimes darker than heartwood on account 
of sapstain.) Rays distinctly visible but fine. The 
wavy tangential lines conspicuous throughout the 
summerwood. Springwood pores numerous, in 
more than one row. Color pale to yellowish or 
greenish gray. Wood moderately heavy. 37. 
HACKBERRY or SUGARBERRY. 4. 
BB. Heartwood distinctly darker than sapwood. Rays 
barely visible. 
(1) Springwood pores in more than one row. 

a. Very fine broken tangential lines visible in outer 
summerwood and especially prominent in wide 
rings. Sapwood several inches wide, heartwood 
brownish. Most pores or vessels except in outer 
sapwood appear somewhat closed, difficult to 



II 



'Figure indicates an average weight per cubic foot of the wood air dry, that 
is, containing 12 to 15 per cent moisture. U. S. Department of Agriculture Bulletin 
556. 

^This number indicates group to which the wood belongs in the box wood classi- 
fication. Pages 100, 104. 



STRUCTURE AND IDENTIFICATION OF WOODS 119 

blow through. Wood hard and heavy except 
pumpkin ash which usually is relatively soft, 
weak and brash. 36-44. 

PUMPKIN ASH. 3. 
WHITE ASH. 4. 

GREEN ASH. 4. 

b. Long and conspicuous wavy tangential bands 
throughout the summerwood. Sapwood very 
narrow. Heartwood brown with reddish tinge. 
Pores rather open. Wood moderately heavy. Z7. 
SLIPPERY ELM. 3. 
(2) Springwood pores in one more or less continuous 
row except in wide rings where there are occasion- 
ally more. Heartwood brownish. 

a. Pores in the springwood fairly conspicuous and 

visible, because of size and closeness together. 
Pores rather open. Wood moderately heavy. 
36. WHITE ELM. 3. 

b. Pores in the springwood inconspicuous, hardly 

distinguishable from those of the summerwood 
because relatively small, often not close to- 
gether, and usually filled with tyloses. Wood 
heavy. 44. 

CORK or ROCK ELM. 4. 
3. Summerwood, generally not figured with radial or tan- 
gential bands. Rays barely visible. Several rows of 
large springwood pores which are usually open and easy 
to blow through. Sapwood narrow, rarely over three- 
fourths of an inch wide. Heartwood grayish to olive 
brown. Wood moderately heavy. 34. (Compare Plate 
XVI, figure 9.) 

BLACK ASH. 3. 
B. Diffuse-porous woods — No ring of large pores found at 
the beginning of each year's growth. Pores appear as 
fine grooves on the longitudinal cuts and are scattered 
with considerable uniformity throughout both the 
springwood and the summerwood. Pores vary in size 
from visible to the naked eye to barely visible or indis- 
tinguishable without a lens. The relatively small 
amount of difference in size between the springwood 
and summerwood pores makes it often difficult to dis- 
tinguish the annual rings. Some of these woods are 
rather soft and light but are separated (because they 



120 WOODEN BOX AND CRATE CONSTRUCTION 

contain pores or vessels) from "II," the conifers, or 
softwoods, which do not have true pores or vessels. 
Dififuse-porous woods are found in groups 1, 3, and 4 of 
the box woods. Those in group 1 are lightest. (Com- 
pare Plate XVI, figures 10 to 12, and Plate XVII, fig- 
ures 1 to 11.) 
AA. Individual pores plainly visible. Heartwood light 
chestnut brown. Sapwood narrow. Rays not vis- 
ible on cross section. Wood light and soft. 27. 
(Compare Plate XVI, figure 10.) 

BUTTERNUT. 1. 
BB. Individual pores barely visible, Sapwood wide. Rays 
not visible on cross section. 
(Compare Plate XV, figures 11 and 12.) 

(1) Pores not crowded. Heartwood reddish brown. 

Wood moderately heavy to heavy. 38-44. 

BIRCH. 4. 

(2) Pores crowded. Heartwood grayish to brownish. 

Wood moderately light to light. 24-28. 

COTTONWOOD. 1. 
WILLOW. 1. 

CC. Individual pores not visible. 

(Compare Plate XVII, figures 1 to 11.) 

(1) Rays comparatively broad and conspicuous, appear 

as flecks on quartered cuts and distinguish these 
woods from conifers. Color various shades of 
light reddish brown. 

a. Rays crowded. No denser and darker band of 

summerwood noticeable. Wood usually lock- 
grained. Moderately heavy. 34. 

SYCAMORE. 3 

b. Rays not crowded. A distinct denser and darker 

band of summerwood present. Wood fairly 
straight-grained. Heavy. 44. 

BEECH. 4. 

(2) Rays not conspicuous but visible, hence distinguish- 

ing these woods from conifers. 
a. Heartwood dingy reddish brown often with 
darker streaks. Sapwood pinkish white mod- 
erately wide, usually over an inch ; often sold 
as "sap gum," sometimes stained blue by sap- 
stain. Annual rings not clearly defined. Rays 
very fine, close together, not plain even on 



STRUCTURE AND IDENTIFICATION OF WOODS 121 

quartered cuts. Wood moderately heavy. 34. 

RED GUM. 3. 

b. Heartwood light reddish brown. Sapwood wide. 

Annual rings clearly defined by a thin darker 
reddish brown layer. Rays fine but distinct, 
conspicuous on quartered cuts because of 
darker color. 

(a) Wood hard, difficult to cut across the grain. 

Pith flecks rare. Rays appear to be not 
very close together as compared with 
soft maple. Wood heavy. 43. 
SUGAR OR HARD MAPLE. 4. 

(b) Wood comparatively easy to cut across 

grain. Pith flecks often abundant. Rays 
appear very close together as compared 
with hard maple. Wood relatively soft 
and only moderately heavy. 32-37. 
SOFT MAPLE. 3. 

c. Heartwood pale to yellowish with a greenish, 

sometimes (especially in yellow poplar) pur- 
plish tinge. Sapwood usually over 1 inch wide. 
Annual rings clearly defined by a fine whitish 
line. Wood moderately light to moderately 
heavy. About 27-35. 

TULIP or YELLOW POPLAR. 1. 

CUCUMBER TREE. 1. 

MAGNOLIA. 1. 

d. Lleartwood pale or creamy brown often with 

scattered dark or black marks or streaks, 
Heartwood not sharply defined from light 
creamy colored sapwood. Wood light. 26. 

BASSWOOD. 1. 
(3) Kays not distinctly visible on cross section. x\n- 
nual rings usually not clearly defined which aids 
in distinguishing these woods from conifers, 
a. Heartwood distinctly darker than sapwood. 

(a) Heartwood, reddish brown. Wood fairly 
straight-grained,, pith flecks sometimes 
found. Pores visible in a good light, 
especially on longitudinal surfaces where 
they appear as fine lines or grooves. 
Wood moderatelv heavv to heavy. 38-44. 
' BIRCH. 4. 



122 WOODEN BOX AND CRATE CONSTRUCTION 

(b) Heartwood pale to grayish brown. Wood 
often very cross grained. Moderately 
heavy. 34-35. 

BLACK GUM. 3. 
TUPELO. 3. 

b. Heartwood not distinctly darker than sapwood. 
Wood odorless, tasteless. 

(a) Color creamy. Annual rings inconspicuous, 

very faintly defined. Tangential surfaces 
show, when smoothly cut, faint fine 
bands running across the grain produced 
by the regularly spaced or storied rays 
"ripple marks." (See Plate XVII, figure 
5.) Wood very light and soft. 25. 
BUCKEYE. L 

(b) Wood whitish. Annual rings clearly de- 

fined by a fine sometimes whitish line. 
No figure such as is produced by storied 
rays. Wood light. 28. 

ASPEN or "POPPLE." 1. 

Conifers 

The softwoods, woods obtained from scale or needle- 
leaved trees. Woods without pores. 

II. No pores present — Wood usually appears fine textured 
because the cells are small and regularly arranged and 
because no cells are strikingly larger than those sur- 
rounding them. Annual rings are clearly defined by a 
definite band of summerwood. Woods light, most of 
them in box wood group 1. A few heavier conifers 
make up group 2 of the box woods. 
A. Odor and taste spicy-resinous. No resin ducts, pitch 
pockets or accumulations of pitch present. 

THE CEDARS. 
(Compare Plate XVIII, figures 1 and 2.) 

1. Color creamy shading to a pale brown. Heartwood 

odor strong in green. material, somewhat suggests 
ginger. Wood moderately light. 31. 

PORT ORFORD CEDAR. 1. 

2. Heartwood various shades of red and brown ; odor 

resembling that of cedar shingles. Wood light to 
very light. 22. RED CEDAR. 1. 

ARBORVITAE. 1. 



STRUCTURE AND IDENTIFICATION OF WOODS 123 

B. Odor and taste not spicy, may be resinous, especially 
in the pines. Pitch pockets and other accumulations 
of pitch, including small exudations on the ends of 
boards, often present. Knots usually more or less 
resinous. Resin ducts present. 
1. Heartwood darker than sapwood. 

AA. Resin ducts visible relatively conspicuous aS 
small light specks on the cross section or 
as fine lines of slightly different color on 
the longitudinal surfaces. Wood with 
pitchy resinous odor or taste. Heartwood 
creamy to orange brown. (Compare Plate 
XVIII, figures 7 to 9.) 

THE PINES. 

(1) Summerwood relatively inconspicuous, not 

much harder or denser than springwood. 
Change from springwood to summer- 
wood gradual. Heartwood pale creamy 
to light reddish brown. Resin ducts 
often conspicuous, especially in sugar 
pine. Wood moderately soft, light. 26-29. 

WHITE PINE. 1. 

SUGAR PINE. 1. 

(2) Summerwood somewhat denser and more 

conspicuous than in (1). Color of heart- 
wood reddish to orange brown. This 
group midway in density and appearance 
between (1) and (3). Weight 28-34. 
WESTERN YELLOW PINE. 1. 
LODGEPOLE PINE. \. 

JACK PINE. ■ L' 

SCRUB PINE. L 

NORWAY PINE. 1. 

(3) Summerwood very dense, horny. Change 

from springwood to summerwood often 
very abrupt. Resin ducts to be seen, 
especially in or near the summerwood. 
Wood heavy. 35-45. 
VIRGINIA AND CAROLINA PINE. 2 
SOUTHERN YELLOW PINE. 2 

PITCH PINE. 2 



124 WOODEN BOX AND CRATE CONSTRUCTION 

BB. Woods with rather inconspicuous resin ducts, 
without piny odor but with somewhat 
resinous odor and taste. Marked and rather 
abrupt change from springwood to sum- 
merwood. Pitch pockets or streaks may be 
found. (Compare Plate XVIII, figures 10 
to 12.) 

(1) Color of heartwood usually reddish, some- 

times with yellow cast. Summerwood 
dense. Scattered resin ducts present. 
Often several seen as small white dots in 
short tangential rows in or near the sum- 
merwood. Pitch pockets common. Wood 
moderately heavy. 30-34. 

DOUGLAS FIR. 2. 

Sometimes (DOUGLAS SPRUCE, 
called (OREGON PINE. 

(2) Heartwood dull russet brown. Summer- 

wood sharply defined and fairly dense. 
Woods moderately heavy, especially that 
from butt cuts. 36. 

LARCH. 2. 

TAMARACK. 2. 

(3) Heartwood pale reddish. Transition from 

springwood to summerwood more grad- 
ual. Split tangential surfaces, especially if 
through the summerwood of narrow 
rings, characteristically indented or "dim- 
pled." (See Plate XIX.) Split, surfaces 
show "silky sheen." 26. 

SITKA SPRUCE. 1. 
2. Heartwood the same color as sapwood. Woods not 
conspicuously pitchy though resin ducts are pres- 
ent and pitch pockets may occur. Gradual transi- 
tion from springwood to summerwood. (Split 
surfaces show "silky sheen.") Moderately heavy. 
24-28. 

OTHER SPRUCES. 1. 

C. Wood without spicy odor, not pitchy or resinous. No 

resin ducts, pitch pockets or accumulations of resin 

normally present in the wood though resin may in 

some cases exude from the bark. 

1. Heartwood strongly colored. Summerwood dense. 



STRUCTURH AND IDRNTinCATION OF WOODS 125 




126 WOODEN BOX AND CRATE CONSTRUCTION 

AA. Heartwood deep brownish red. Wood with- 
out markedly characteristic odor. Annual 
rings regular in width. Wood moderately 
light. 25-30. 

REDWOOD. 1. 
BB. Heartwood light to very dark brown. Odor 
somewhat rancid. Longitudinal surfaces 
feel waxy. Annual rings very irregular in 
width. Weight variable. Average 30. 

CYPRESS. 1. 
2. Heartwood not strongly colored. 

AA. Wood whitish at least in springwood. Sum- 
merwood darker, often sharply contrasted 
in color, tinged with red or purplish brown. 
Wood moderately light to light. 23-28. 
THE TRUE FIRS. 1. 
BB. Wood has slight reddish hue in both spring- 
wood and summerwood. Wood splintery, 
often with cup shake. Odor somewhat sour 
when wood is fresh. Moderately light. 28. 
HEMLOCK. 2. 

DESCRIPTION OF BOX WOODS 

The letters after the names refer to the various regions 
in which the trees grow as indicated on the accompanying 
map, figure 30, although the geographical distribution of each 
species is not confined exactly to the limits of the regions 
indicated. For scientific 'names see U. S. Dept. Ag. Bui. 17, 
"Check List of Forest Trees." 

HARDWOODS 

RiNG-PoRous Woods 

The Oaks — White oak group (A, B, C, D, E). 
Red oak group (A, B, C, D, E). 

These species grow throughout the eastern half of the 
United States. 

They are heavy and hard and when dry are without char- 
acteristic odor or taste. The annual rings are very distinct 
in both the white and the red oaks. Under a lens the pores 
of the summerwood of the white oaks are very minute and so 
numerous that they are difficult to count, but in the red oaks 
the opposite is true, which makes these species easy to dis- 



STRUCTURE AND IDENTIFICATION OF IVOODS 127 

tinguish. (Compare figures 1 and 2, Plate XVI.) The most 
characteristic feature of all oak woods is the presence of 
broad medullary rays very conspicuous on the end surface 
and appearing on the radial surface as silvery patches from 
3^ to 4 inches in height with the grain. This structure dis- 
tinguishes the oaks from all other woods. 
Chestnut (B, D). 

The region of growth is the Appalachian highland and 
the central hardwood section. 

The wood of chestnut is moderately light and usually 
straight-grained. The heartwood is grayish brown, with a 
slightly stringent taste due to the tannin in it. The annual 
rings are made very distinct by a broad band of porous spring- 
wood. The pores in the summerwood are very numerous and 
arranged in irregular radial bands similar to those in white 
oak. (See figure 3, Plate XVI.) The rays are much finer, 
however, than in the oaks. 
The Elms— White dm (A, B, C, D, E). 
Cork elm (B, D). 

The range of white elm is the eastern half of the United 
States, that of cork elm being confined to the Appalachian 
highland and the central hardwood section. 

The wood of white elm is moderately heavy and easy to 
work ; that of cork elm is heavier, harder, and ranks higher 
in mechanical properties. 

In both white and cork elm the springwood usually con- 
sists of but one row of large pores, those of the latter being 
smaller and filled with tyloses in the heartwood. (See fig- 
ures 4 and 5, Plate XVI.) 
Hackberry — (B, D, E, F, parts of G and H). 

The range of growth includes Montana, Idaho, and the 
eastern half of the United States, except the northern portion. 

The wood of hackberry is moderately heavy and generally 
straight-grained. The heartwood is light gray, tinged with 
green, which helps to distinguish this species from the elms 
in which the heartwood is brownish, usually with a reddish 
tinge. It is without characteristic odor or taste. The rays 
and annual rings are distinct without a lens which also helps 
to distinguish it from the elms. (See figure 7, Plate XVI.) 
The Ashes— rF/ti?^ ash (A, B, C, D, E). 
Green ash (A, B, C, D, E). 

Black ash (A, C, and northern part of B and D). 
Pumpkin ash (Parts of E and western D). 



128 WOODEN BOX AND CRATE CONSTRUCTION 

The range of Avhite and green ash is the eastern half of 
the United States ; of black ash, the northern part of this sec- 
tion, and that of pumpkin ash, the southern portion. White 
and green ash are very much alike and are sold as "white ash" 
or "ash." The lighter weight grades of white and green ash 
are commercially classed as "pumpkin ash." 

The sapwood of each is comparatively wide and white. 
The heartwood is grayish brown occasionally with a reddish 
tinge. In black ash the sapwood is narrow, usually less than 
one inch wide and the heartwood is silvery or olive brown, 
resembling that of chestnut. Black ash averages consider- 
ably lighter in weight than the other two species. 

All species have definite annual rings made very con- 
spicuous by several rows of large pores in the springwood. 
In the summerwood the pores are few, very small, and iso- 
lated, or occasionally two or three in a radial row. Except in 
black ash, these pores are surrounded by light colored tissue 
which projects tangentially, producing light-colored lines often 
joining pores somewhat separated, especially in the outer por- 
tion of the annual rings. (See figures 8 and 9, Plate XVI.) 
Elm can be distinguished from ash by the arrangement of its 
numerous summerwood pores in wavy tangential lines. 

Diffuse-Porous Woods 

Butternut— (A, B. D). 

The range of growth is the northeastern part of the 
United States, including the central hardwood section. 

Butternut resembles black walnut in structure but is 
lighter in weight, softer and lighter colored, resembling black 
ash or chestnut in this respect. It differs from the woods 
previously discussed in that it has no very pronounced group 
of springwood pores. 
Birch— (A, B, C, D, E). 

These species grow chi-efly in the northern portion of the 
United States, east of the Mississippi River. 

The structure of the different birches is very similar. 
The wood is heavy, fairly straight-grained and without char- 
acteristic odor or taste. The pores are barely Ansible to the 
naked eye on the cross section but quite readily visible as 
grooves on the longitudinal surfaces. The annual rings, be- 
cause of the almost uniform size of the pores, are rather in- 
distinct. Pith flecks are very often present in birches. 

The birches may be confused with the maples. In the 



STRUCTURE AND IDENTIFICATION OF WOODS 129 

maples, however, the rays on the cross section are visible to 
the naked eye, while in the birches they are not. Further- 
more, the pores of the maples are not visible to the naked eye, 
v/hile those of the birches can generally be seen when the 
wood is examined in a good light. 
Cottonwood— (B, C, D, E, F). 
Aspen— (A, B, C, D, F, G, H, I). 

The range of growth of cottonwood is all of the eastern 
section of the United States except New England and the 
northern part of the Rocky Mountain section ; that of aspen 
is all sections of the United States except the South At- 
lantic and Gulf States. 

Both species are light, fairly straight-grained, and with- 
out characteristic odor or taste. 

There is practically no difference in color between the 
sapwood and heartwood of either species. The pores are 
larger in cottonwood than in aspen. The rays are not readily 
visible to the naked eye. (See figure 12, Plate XVI, and fig- 
ure 3, Plate XVII.) 

Cotton gum or tupelo resembles cottonwood but usually 
is heavier and has smaller pores. Yellow poplar is similar in 
weight and hardness but its greenish tinge usually distin- 
guishes it. Basswood has more of a creamy white color, 
smaller pores, and distinct rays. 
Sycamore— (A, B, C, D, E). 

The range is the eastern half of the United States. 

The wood is moderately heavy, usually lock-grained, 
without characteristic odor or taste. The heartwood is col- 
ored from light to a moderately dark reddish brown, some- 
times not clearly defined from the sapwood. The pores are 
very small and crowded together. The rays are very charac- 
teristic; they are comparatively broad and conspicuous, al- 
though not as large as the largest rays in the oaks. They are 
all practically of the same size. On the radial surface they 
appear as reddish brown "flakes," similar to the rays in oak, 
but smaller. 

Sycamore is not easily confused with other woods. Its 
conspicuous rays and interlocked grain make it easily recog- 
nizable. (See figure 6, Plate XVII.) It resembles beech 
somewhat, but can be distinguished from it by the rays, only 
a small portion of which are broad in beech. Beech also is 
heavier and has a distinct dense band of summerwood. 



130 WOODEN BOX AND CRATE CONSTRUCTION 

Beech— (A. B, D, E, eastern half of C). 

This species grows in the eastern section of the United 
States and also in northern Wisconsin. 

Beech is a hard heavy wood without characteristic odor 
or taste. The heartwood has a reddish tinge varying from 
light to moderately dark. The pores are invisible without a 
lens and decrease in size slightly and gradually, from the in- 
ner to the outer portion of each ring. (See figure 7, Plate 
XVII.) Some of the rays are broad, being fully twice as wide 
as the largest pores and appearing on the radial surface as 
reddish brown flakes. The other rays are very fine. The 
maple resembles beech, except that in maple the widest rays 
are about the same width as the largest pores and not so con- 
spicuous on the radial surface. 
Red gUm — (D, E, and part of B). 

Red gum grows in the Appalachian section and in the 
Gulf States. 

It is moderately heavy, somewhat lock-grained, and with- 
out characteristic odor or taste. The sapwood is white with 
a pinkish hue or often blued with sapstain. The heartwood 
is reddish brown, often with irregular darker streaks. The 
wood has a very uniform structure. The annual rings are in- 
conspicuous and pores are not distinct to the unaided eye, but 
the rays are fairly distinct without a lens. (See figure 8, Plate 
XVII.) The uniform structure, interlocked grain, and red- 
dish brown color are usually sufificient to distinguish red gum 
from other woods. 
The Maples—Sugar maple (A, B, C, D, E). 

The range of growth of this species is the eastern half of 
the United States. 

Sugar maple is heavy, hard and difficult to cut across the 
grain, in which respect it differs from the softer maples. The 
sapwood is white in all maples, and the heartwood is light 
reddish brown, without characteristic odor or taste. The an- 
nual rings are defined by a thin reddish layer usually more 
conspicuous on dressed longitudinal surfaces. The pores are 
all very small and uniformly distributed throughout the an- 
nual ring. The rays are distinct without a lens and on radial 
surfaces they are conspicuous as small reddish brown flakes. 
In sugar maple only part of the rays are as wide as the pores ; 
the others are very fine, being barely visible with a lens. The 
differences between the soft and hard maples are similar to 
those distinguishing, sycamore and beech, although in the 



STRUCTURE AND IDENTIFICATION OF WOODS 131 

maples the rays are finer. In soft maple the rays are crowded 

as in sycamore. Birch and beech resemble ma])le somewhat. 

Birch has larger pores, visible as fine grooves on the dressed 

surfaces and the rays on the end surfaces are not distinctly 

visible without a lens. In beech some of the rays are very 

conspicuous. 

Yellowr poplar— (B, D, E). 

The range of growth is the Appalachian highland, the 
central hardwood section and Gulf States. 

Yellow poplar is moderately light, straight-grained, and 
without characteristic odor or taste. The heartwood is light 
to a moderately dark yellowish or olive brown with a green- 
ish and sometimes ])urplish tinge or streaks. The annual 
rings are outlined by light-colored lines. The pores are evenly 
distributed throughout the annual ring, and are too small to 
be visible to the unaided eye. The rays are distinct without 
a lens. (See figure 1. Plate XVII.) 
Cucumber tree — (B, D, E). 

The cucumber tree grows in the same locality as yellow 
poplar except in Florida and the South Atlantic Coast. 

It is easily confused with yellow poplar and is usually 
sold as such, although it averages slightly heavier in weight. 
It is much inclined to stain. 
Basswood— (A, B, C, D). 

This species grows in the eastern half of the United 
States. 

It is a light, soft, straight-grained wood with a creamy 
brown color. The heartwood is not clearly defined from sap- 
wood. Sometimes black or brownish spots or streaks are 
present. It is without taste, but has a slight characteristic 
odor even when dry. The pores are invisible without a lens. 
The rays are fairly distinct on the end surface. (See figure 
11, Plate XVII.) 

Cottonwood resembles basswood, but is more grayish in 
color, has larger pores, and very fine rays. Buckeye also re- 
sembles basswood in color and texture, except that the rays 
are much finer and are visible on the cross section only with 
a good lens. They form characteristic so-called "ripple 
marks" on the tangential surfaces. (?ee figure 4, Plate 
XVII.) 

The Gums— 7?/ar^ giun (A, B, D, E). 
CoHon gum (southern D, E). 

Black gum grows in the eastern half of the United States, 



132 WOODEN BOX AND CRATE CONSTRUCTION 

except in northern Michigan, Wisconsin, and Minnesota, and 
cotton gum in the Southern Atlantic and Gulf States. 

These woods are moderately heavy to heavy, very lock- 
grained. They are without characteristic odor or taste. The 
annual rings are indistinct. The rays and pores are not dis- 
tinct to the naked eye. The weight, lock grain, and lack of 
well defined summerwood distinguish these woods from the 
conifers. Their lack of distinctive characters assists in their 
identification. Cotton gum is often lighter and softer in the 
butt log than near the top. Cottonwood sometimes resembles 
tupelo, or cotton gum, but its more visible pores serve to 
identify it. (See figure 2, Plate XVII.) 
Yellow buckeye — (D). 

The range of growth of this species is the Appalachian 
highland, the Ohio valley, and into Texas. 

This wood is light, soft, straight-grained, and without 
characteristic odor or taste. The heartwood is not clearly 
differentiated from the sapwood. The general color of the 
wood is creamy white or yellowish. The annual rings are 
often not clearly defined. The pores and rays are not visible 
to the naked eye, although characteristic "ripple marks," pro- 
duced by groups of rays, may be seen on tangential surfaces. 
(See figures 4 and 5, Plate XVII.) Buckeye resembles bass- 
wood but the rays in basswood, though fine, can be distin- 
guished more readily than those in buckeye. Buckeye also 
somewhat resembles aspen. 

Conifers (Non-Porous Woods) 

The Cedars — Western red cedar {^). 

In the United States this species grows in the northwest- 
ern part, chiefly in Washington and Oregon. 

The western red cedar is light and straight-grained. The 
heartwood is reddish-brown, with the characteristic odor of 
cedar shingles and a somewhat bitter taste when chewed. 
The wood contains no resin ducts, although it contains a 
small quantity of aromatic oils. The annual rings are dis- 
tinct, moderate in width, with a thin, but well defined band 
of summerwood. Pores are entirely absent, and the rays are 
very fine. (See figure 2, Plate XVIII.) 
Northern white cedar (A. B. C). 

The range of growth is the northern part of the United 
States from Maine to Minnesota. 

This species resembles western red cedar in odor and 



STRUCTURE AND IDENTIFICATION OF WOODS 133 

taste, but usually it is without the reddish hue, has very nar- 
row annual rings, and averages lighter in weight. 
Port Orford cedar (H). 

This species grows in southwestern Oregon and north- 
western California. 

It is a moderately light, straight-grained wood with a 
pronounced odor and taste ; the odor is sometimes compared 
to that of ginger. The wood is less spongy than that of 
some of the other cedars. The odor and light color make the 
identification of this wood easy. (See figure 1, Plate XVIII.) 
The White Pines — Eastern white pine (A, B, C and parts of 
D). 

Western white pine (F, H, I). 

The region of growth of eastern white pine in the United 
States is the northern part from Maine to Minnesota, and 
that of western white pine, the northwestern part. 

The wood of both these species is moderately light, 
straight-grained and practically tasteless, but has a slight, 
yet pleasant and distinct resinous odor. The heartwood is 
creamy to light reddish or yellowish brown. The annual 
rings are distinct, but the summerwood is not a pronouncedly 
darker or appreciably harder layer. The outer portion of 
western yellow pine logs often has narrow annual rings with 
a very thin layer of summerwood so that this species may 
approximate the white pines in appearance, and consequently 
is often sold as white pine. It may be distinguished, how- 
ever, by its horny glistening layers of summerwood, which 
are especially prominent in the wider rings. 
Sugar pine (I ). 

Sugar pine grows in the northern part of California and 
in Oregon. 

It is very much like the white pines in structure and 
properties, and in fact belongs to the white pine group bo- 
tanically. The heartwood is very light brown, only slightly 
darker than the sapwood and practically never reddish, as is 
the case, quite often, in the white pines. The summerwood 
never appears as a horny, glistening band as in the hard 
pines. The wood of sugar pine has a slightly coarser texture 
than that of white pine ; that is, the fibers and also the resin 
ducts have a greater average diameter. Resinous exudations, 
which become granular and have a sweetish taste, are quite 
common in rough sugar pine lumber, and when present are 
the more reliable mieans of distinguishing it from the other 
pines. (See figure 7, Plate XVIII.) 



134 WOODEN BOX AND CRATE CONSTRUCTION 

The Yellow or Hard Pine Group — Western vellow pine (F, G, 

H, I). _ 
Norway pine (A, C, northern half of B). 
Southern yellozv pine (E). 

These species range as follows : western yellow pine, in 
the Rocky Mountain and Pacific slopes ; the southern yellow 
pine, in the South Atlantic and Gulf States, and Norway pine 
in the Northeastern and Central States. 

The yellow pines are mostly heavier, harder, more resin- 
ous, and contain a wider and harder layer of summerwood 
than the white pines. However, exceptions occur, notably 
western yellow pine, which in the outer part of the mature 
trees is often as light in weight as the average white pine. 
In the dififerent species and even in the same species the sap- 
wood is variable in width, averaging narrowest in some spe- 
cies of southern yellow pine. The heartwood is orange- 
brown to reddish-brown color. The summerwood is usually 
defined as a conspicuously denser, harder, and darker band, 
but in very narrow rings such as are found in the sapwood of 
old trees of western yellow pine the summerwood layer may 
be very narrow and inconspicuous. The resin ducts are vis- 
ible with a lens on a smoothly-cut end surface, and may be 
seen as brownish or whitish lines on the longitudinal surfaces. 
Douglas fir is somewhat similar to yellow pine in appear- 
ance, but usually has a distinct reddish hue and less prominent 
resin ducts. 
Douglas fir— (F, G, H, I). 

Douglas fir grows abundantly in the Pacific Northwest 
and throughout the Rocky Mountain region. 

It differs from the true firs in being more resinous, 
heavier, stronger and in having a distinctly darker heartwood. 
The annual rings are made distinct by a conspicuous band 
of summerwood. Resin ducts are present, but not so distinct 
as in the pines, usually appearing on a cross section as whitish 
specks in the summerwood. (See figure 10, Plate XVIII.) 
The Spruces — White spruce (A, B, C). 
Red spruce (A, B). 
Sitka spruce (H). 
Engelmann spruce (G, F). 

White spruce grows in the northern part of the United 
States east of the Mississippi, red spruce in the same section, 
except in the western part, Sitka spruce in western Wash- 
ington and Oregon, and Engelmann spruce in the Rocky 
Mountain highland. 



STRUCTURE AX I) I DENT I TIC AT I OK OE ll'OODS 135 

These species are moderately light, straight-grained 
woods. In the white, red, and Engelmann spruce, the heart- 
wood is as light colored as the sapwood, but in Sitka spruce 
the heartwood has a light reddish tinge, making it a little 
darker than the sapwood. The annual rings are clearly de- 
fined by a distinct but not horny band of summcrwood. 
Spruce resembles the white pines in texture but has a silky 
sheen. (See Plate XIX.) On account of its reddish 
tinge Sitka spruce might be confused with light grades 
of Douglas fir from which it can be distinguished, however, 
by the pocked or dimpled appearance of split tangential sur- 
faces. (See Plate XIX.) Douglas fir has denser summer- 
wood except in very narrow rings ; therefore, rings of aver- 
age width should be compared. Engelmann spruce is some- 
what lighter in weight and weaker than the other spruces. 
Bald cypress (E). 

This species grows abundantly in the South Atlantic 
and Gulf States. 

It is highly variable in color and weight. Commercially, 
the common cypress is classed as "white," "yellow," "red," or 
"black" cypress, although it is all derived from the same 
botanical species. The wood has a characteristic rancid odor 
when fresh. In dry wood the odor is less pronounced, but 
can be detected by sawing it and holding the sawdust to the 
nostrils. The wood is without characteristic taste. The an- 
nual rings usually are irregular in width and outline. The 
summerwood is very distinct but narrow, although wider than 
in the cedars. (See figure 3, Plate XVIII.) Cypress resem- 
bles the cedars and redwood somewhat ; but the cedars have 
an aromatic odor and spicy taste, and redwood is tasteless 
and odorless. 
Redwood (I, along the coast). 

Redwood grows in the coast region of northern Cali- 
fornia. 

It is moderately light, straight-grained and obtainable in 
large clear pieces. The heartwood, as a rule, is deep reddish 
brown in color. Occasionally, lighter colored pieces, resem- 
bling western cedar, are found. The wood contains nc^ resin 
ducts. The annual rings are made very distinct by dense 
bands of summerwood alternating with soft, spongy spring- 
wood. (See figure 6, Plate XVIII.) Redwood is without 
characteristic odor or taste. 



136 WOODEN BOX AND CRATE CONSTRUCTION 

The True Firs— Balsam fir (A, B, C). 

Noble fir (H). 

White fir (G, I). 

Red fir (I). 

Alpine fir (F, G,Ii). 

With the exception of balsam fir these species grow 
abundantly in the Rocky Mountain highland and on the 
Pacific slopes. 

They are all moderately light, straight-grained and with 
the exception of Alpine fir, practically without characteristic 
odor or taste. Alpine fir has, when dry, a distinctly disagree- 
able odor. The color of the wood is whitish, often with a red- 
dish brown tinge, which is especially noticeable in the sum- 
mer wood bands. This produces a sharp color contrast in each 
ring which is a very distinctive character in most of the 
woods of this group. The wood is very uniform. Rarely 
short lines of resin ducts resulting from injury may be found. 
The firs resemble hemlock but the weight and difference in 
color between springwood and summerwood are often suffi- 
cient to distinguish them. 
Hemlock— Hemlock (A, B, C, D). 

Western hemlock (F, H). 

Hemlock grows in the eastern half of the United States, 
except in the southeast portion. The range of growth of 
western hemlock is the northwestern part of the United States. 
These woods are about medium in weight but are grouped 
with the heavier conifers for box and crate construction. 
They are usually straight-grained, sometimes twisted, and the 
eastern species is often splintery and subject to cup shakes. 
When fresh, hemlock has a characteristic sour odor, but this 
practically disappears when the wood is dry. There is little 
difference in color between sapwood and heartwood, although 
the latter may have a somewhat pale brown or reddish hue. 
There is no striking contrast in color between the spring- 
wood and summerwood such as is generally found in the firs, 
the change of color in the hemlocks is gradual. The rays in 
hemlock are not visible to the naked eye and the wood does 
not normally have resin ducts. The western hemlock is less 
splintery and subject to cup shakes than the eastern species. 
Tangential lines of abnormal resin ducts caused by injuries 
are present, especially in the western species. 



STRUCTURE AND IDENTIFICATION OF WOODS 137 
GRADING RULES FOR ROTARY-CUT BOX LUMBER 

The following rules, revised May 20, 1919, are used by 
the Rotary Cut Box Lumber Association : 

Specifications shall always be furnished by buyer to man- 
ufacturer as follows : 

Thickness First 

Width across grain Second 

Length with grain Third 

1. All stock shall be log run, the full cut of the log, and 
shall be free from rot or dote. Pin-worm holes, sound tight 
knots, discoloration, and stain are no defect. 

2. All stock shall be machine-cut to thickness, standard 
gears as furnished by lathe manufacturers to be used. 

3. All stock shall be cut tight, and, when shipped, shall 
weigh not to exceed 3,100 pounds per thousand board feet if 
kiln-dried, or 3,400 pounds per thousand board feet if air- 
dried, railroad weights at point of shipment to govern. Stock 
shall be sufficiently fiat to straighten under machine without 
splitting. 

4. A trimming allowance of J.^ inch in length shall be 
made on all stock up to 30 inches long and of 1 inch on stock 
longer than 30 inches, all lengths to have j^-inch trimming 
allowance in width ; but if not to exceed 25 per cent in any 
one car shall measure scant of the 3^-inch trimming allow- 
ance in widths, but full V^. inch, it shall be considered up to 
specifications. 

5. All cut-downs in width that accumulate in cutting out 
defects and rounding logs shall be accepted by buyer, these 
cut-downs to run in 2-inch multiples down to 4 inches, unless 
otherwise agreed ; but not over 25 per cent of contents of any 
car, feetage basis, shall consist of these cut-downs. When 
sawed after drying, these cut-downs may be exact width ; but 
if they are sized green, a ^-inch trimming allowance, when 
dry, shall be made. 

6. Checks or splits not longer than one-fourth the length 
of the piece, but in not more than 15 per cent of the pieces in 
each shipment, are allowed, provided these checks or splits 
are reasonably straight, or do not diverge more than 2 inches 
per foot, and do not run over ^2 inch in width on pieces 18 
inches and up wide, not over y% inch on pieces 12 to 18 
inches wide, not over 34 i"ch on pieces 6 to 12 inches wide, 
and not over ^ inch on pieces 6 inches and under wide. 



138 WOODEN BOX AND CRATE CONSTRUCTION 

Splits or checks % inch and under wide are not considered 
defects. 

7. Specifications on all sizes, both width and length, 
shall not be divided in fractions of less than j/4 inch. 

Other Species — The minor kinds of boxwoods are graded 
as follows: The hardwoods, sycamore, ash, etc., may be or- 
dered as No. 2 common, according to the rules of the two 
hardwood associations. Larch covers eastern tamarack 
(Northern Pine Manufacturers' Association rules) and west- 
ern larch (Western Pine Manufacturers' Association rules). 
Noble fir, white fir, and red fir are admitted in No. 3 common 
under the West Coast Lumbermen's Association rules. In 
California, white fir and red fir are sold with the box grades 
of California pine. Cedar includes southern red (no standard 
rules), northern white (no standard rules), southern white 
(no commercial rules but see Navy specification 3903b), and 
western red cedar (West Coast Lumbermen's Association and 
Pacific Lumber Inspection Bureau). Redwood may be or- 
dered as merchantable in accordance with the rules of the 
California Redwood Association. 



APPENDIX 



Table 


15. Cement-coated Coolers or 


Standard Nails 


AND Sinkers or 








Countersunk Nails 






















Net 










Dimension 


of Heads 




weight 
per keg 


















Number 




Gauge 


Coolers^ 


Sinkersa 


pounds 


Size 


of nails 
per keg 


Length 


of 
wire 












inches 


Diam- 


Thick- 


Diam- 


Thick- 












eter 


ness 


eter 


ness 


Pounds 










inches 


inches 


inches 


inches 




2d 


85,700 


1 


16 


11/64 


.016 


5/32 




79< 


3d 


54,300 


VA 


15>i 


3/16 


.013 


3/16 




64* 


4d 


29,800 


iH 


14 


7/32 


.029 


13/64 


3 g 


61* 


5d 


25,500 


\% 


13M 


15/64 


.023 


7/32 


2^ 

4j y 


70* 


6d 


17,900 


m 


13 


1/4 


.027 


7/32 


c-5 


65* 


7d 


15,300 


2K 


121^ 


1/4 


.025 


15/64 


^Z 


72* 


8d 


10,100 


2H 


11^ 


19/64 


.025 


17/64 


u > 


71 


9d 


8,900 


2% 


IIM 


9/32 


.029 


17/64 


^o 


68 


lOd 


6,600 


2% 


11 


5/16 


.033 


9/32 


J2 *^ 


63 


12d 


6,200 


SVs 


10 


11/32 


.030 


21/64 


bDji 


80 


16d 


4,900 


SH 


9 






21/64 






20d 


3,100 


3M 


7 


»c 


»o 


11/32 


p s 


83 


30d 


2,400 


4M 


6 


<u 


V 


13/32 




84 


40d 


1,800 


4^and 


5 


o 

c 


o 

c 


15/32 


82 to 85 






4M 




o 


o 




en 1 




50d 


1,300 


5H 


4 


s 


«£ 


1/2 




79 


60d 


1,100 


55^and 

5H 


3 


4J 
0) 


0) 


9/16 


c ^ 

.3 0) 

C71 J= 


82 



^Coolers and sinkers are identical in dimensions and count, differing only 
in the heads. 

-The cooler head is flat and of good size, preferred by many for machine- 
driving and in work where large diameter is desired. It is perfectly satisfactory 
for hand-driving in soft wood. 

^The sinker head is reinforced by a slight countersinking, which reduces the 
diameter. It will not break or pull o(T, and is recommended for hand-driving in 
hardwood. It can be used in automatic nailing machines. 

■•Weights of some manufactures are one-half pound more. 

'The sinker type of head is used on coolers larger than 12d ; the larger sizes 
are, therefore, identical in every particular. 

Either of these types may be used for box and crate work if regular cement- 
coated box nails are not available. 



139 



140 WOODEN BOX AND CRATE CONSTRUCTION 

Table 16. Cement-coated Box Nails* 











Diameter 


Thickness 


Net Weight 




Number 


Length 


Gauge 


at 


of 


per 


Size 


of nails 


inches 


of 
wire 


head 


head 


keg 










Inches 


Inches 


Pounds 


2d 


96,200 


Ktoi 


16^ 


5/32 


.016 


671^ to 74 


3d 


64,600 


IVs 


151^ or 16 


3/16 


.016 


68 to 80 


4d 


45,500 


\% 


15H 


3/16 


.017 


64 to 72}i 


5d 


39,700 


m 


15 


7/32 


.016 


74 to 78 


6d 


23,600 


VA 


13H to 14 


1/4 


.022 


673^ to 77 


7d 


19,300 


2H 


13 to 13H 


1/4 


.022 


69 to 72 


8d 


14,000 


2M to 2% 


i2y2 


17/64 


.024 


70 to 75 ■ 


9d 


13,100 


2J^to2^ 


12M 


17/64 


.034 


71 to 78 


lOd 


8,900 


•2% 


im 


9/32 


.037 


69K to 75 


12d 


8,700 


3^ 


iiH 


9/32 


.031 


80 to 80 J^ 


16d 


7,100 


Ws 


11 


5/16 


.030 


78 


20d 


5,200 


SVs 


10 


11/32 


.036 


83 


30d 


4,600 


4^ 


10 


3/8 


.030 


81 


40d 


3,500 


4K 


I 9 


7/16 


.034 


84 



^The variation in some values is due to the diflference in the manufacturing 
cpecifications of the several manufacturers. 



Table 17. Miscellaneous Cement-coated Nails 













Size of hea 


i Net 






Number 
of nails 










Type of nail 


Size 


Length 


of 


Diam- Th 


ck- [per keg 






per keg 


inches 


wire 


eter ne 
inches inc 


ss 1 pounds 
hes <tt i»H 


Egg Case 


2d 


73,500 


1 


16 


3/16 .0 


13 70 


u u 


3d 


51,700 


iVs 


15 


1/4 .0 


20 70 


u u 


4d 


30,500 


1^ 


14 


9/32 .0 


24 70 


Orange Box. . . 


4d 


55,000 


m 


15 


13/64 .0 


20 81 


Fruit Box 


4d 


45,500 


1^ 


15 


13/64 .0 


11 73 


Apple Box. . . . 


. 5d 


31,000 


iVs 


14 


7/32 .0 


19 74 


Berry Box .... 


. H" 


140,000 


M 


17 


5/32 .0 


11 70 


« u 


■ Vs" 


125,000 


Vs 


17 


5/32 .0 


13 70 


Veneer Box^ . . 


4d 


30,500 


W2 


14 


9/32 .0 


18 70 


Veneer^ 


4d 


19,700 


Ws 


12 


5/16 .0 


20 70 


" 




5d 


13,000 


IVs 


11 


3/8 .0 


21 70 


a 




. 6d 


9,000 


m 


10 


1/2 .0 


29 70 


Barrel .... 




. H" 


95,000 


M 


15^ 




70 


(I 




Vs" 


67,200 


% ■ 


143^ 






70 


H 




1 


55,000 


1 


14M 






70 


U 




. IVs 


48,000 


1% 


14^ 






70 


U 




■ IM" 


37,000 


1^ 


14 






70 


u 




. m" 


26,000 


1% 


13 






70 


u 




. iH 


24,500 


1^ 


13 






70 



*For hooplesa orange boxes. 

'For use in 3-ply veneer packing cases. 



APPENDIX 



141 



NAMES AND DESCRIPTION OF GRADES OF LUMBER 
SUITABLE FOR PACKING BOXES 

White pine' 



ITEM 



White Pine Associa- 
tion of the Tona- 
wandas, North Tona- 
wanda, N. Y. 



Northern Pine 
Manufacturers Asso- 
ciation, Minneapolis, 

Minn. 



Western Pine Man- 
ufacturers Associa- 
tion, Spokane, Wash. 



Box grade 



No. 1 box 

This grade admits 
coarse knots, re- 
gardless of size 
and not necessa- 
rily sound, also a 
reasonable amount 
of shake or stain. 



Higher grade 



No. 3 barn 



No. 4 common 

1. The predominat- 
ing defect charac- 
terizing this grade 
is red rot. 

2. Other types are 
pieces showing 
numerous large 
worm holes, or 
several knot holes 
or pieces that are 
extremely coarse, 
knotted, waney, 
shaky, or badly 
split. 

3. Pieces which are 
extremely cross 
checked are ad 
missible in this 
grade. 

No. 3 common 



Western (Idaho) 
white pine. 
No. 4 common 

1. The predominat- 
ing defects charac- 
terizing this grade 
are red rot and 
knot holes. 

2. Other types are 
pieces showing 
numerous large 
worm holes, pieces 
that are extremely 
coarse, knotted, 
waney, or showing 
excessive heart 
shake, extremely 
pitchy, or badly 
checked or split. 



No. 3 common 



^No standard rules for New England white pine box lumber are in effect at the 
present time (1921). 



142 



WOODEN BOX AND CRATE CONSTRUCTION 



White pine — Continued 



ITEM 



Lower grade 



Thicknesses, 
inches: 
Rough 

S1S\ 
S2S/ 

Widths, inches. 



Length, feet. 



White Pine Associa- 
tion of the Tona- 
wandas, North Tona- 
wanda, N. Y. 



Northern Pine 
Manufacturers Asso- 
ciation, Minneapolis, 
Minn. 



No. 2 box 



1, IVi, I'A, 2, 2J^, 
3, 4. 

'Jla/Not adopted by 
VaX Ass'n. 

4, 5, 6, 8, 10, 12, 13 
and wider, 4 to 16 
with average of 9 
or better, 4 to 12 
averaging at least 
8 may be specified. 



6, 8, 10, 12, 14 and 
16. 6 to 16 aver- 
aging at least 12 
may be specified. 



No. 5 common 



Short box — in- 
cludes lumber 12 
to 47 inches long 
inclusive, 3 inches 
and wider, and 
No. 4 and better. 



1, m, I'A, 2. 
.ii,iK,i^,iM. 

[Same as SIS. 

Mixed widths, 4 
and wider, or in 
specified widths 
of 4, 6, 8, 10, 12, 
13 and wider. 
Average of 9 may 
be specified if 
ordered 4 to 16. 
Best to order 4 to 
12 averaging at 
least 8. 

S2E— H off. 

6, 8, 10, 12, 14, 16, 
18 or 20. 6 to 16 
averaging at least 
12 may be speci- 
fied. 



Western Pine Man- 
ufacturers Associa- 
tion, Spolcane, Wash. 



No. 5 common 



fl, 1^,11^, 2. 
II, 1>^, 1^, IH. 
Same as SIS. 

Sold in mixed 
widths, 4 and 
wider. 



S2E- 



off. 



Sold in mixed 
lengths, 6 and 
longer. 6 to 16 
averaging at least 
12 may be speci- 
fied. 



APPENDIX 



143 



Yellow pine, including North Carolina pine 



ITEM 



Southern Pine Association, New 
Orleans, La. 

Georgia-Florida, Sawmill Asso- 
ciation, Jacksonville, Fla. 



Nortl^ Carolina Pine Association, 
Norfolk, Va. 



Box grade 



Southern yellow pine. 
No. 2 common 

No. 2 common boards dressed 
one or two sides; admits 
knots not necessarily sound, 
but the mean or average di 
ameter of any one knot must 
not be more than one-third 
of the cross-section if 
located on the edge and 
must not be more than one- 
half of the cross-section if 
located away from the edge; 
a sound knot may extend 
over one-half the cross- 
section if located on the edge, 
except that no knot the mean 
or average diameter of which 
exceeds 4 inches is admitted; 
admits also worm holes, 
splits one-fourth the length 
of the piece, wane 2 inches 
wide, or through heart 
shakes one-half the length 
of the piece, through rotten 
streaks 3^ inch wide one- 
fourth the length of the 
piece, or its equivalent of 
unsound red heart; or defects 
equivalent to the above. 

A knot hole 3 inches in di- 
ameter will be admitted, pro- 
vided the piece is otherwise 
as good as No. 1 common. 
Miscut 1-inch common 
boards which do not fall 
below % inch in thickness 
are admitted in No. 2 com- 
mon, provided the grade of 
such thin stock is otherwise 
as good as No. 1 common. 



North Carolina pine. 

Box 

Lumber below the grade of 
No. 3, containing pinholes, 
pin, standard, and large, 
reasonably sound knots, 
stain not e.xceeding 25 per 
cent, and pith knots, en- 
cased knots, and spike knots 
which do not seriously afifect 
strength of piece; stained 
pieces otherwise No. 1 and 
2 grade, which show over 50 
per cent stain, and stained 
pieces otherwise grading 
No. 3 and showing not more 
than 321^ per cent stain; and 
pitchy pieces which are not 
desirable in No. 1, 2 and 3 
grades. Lumber which 
would otherwise grade No. 1, 
2 and 3 containing 50 per 
cent firm red heart will be 
admitted in this grade. 
Reverse side of box boards 
may be cull. ' 



144 



WOODEN BOX AND CRATE CONSTRUCTION 



Yellow pine — Continued 



ITEM 



Higher grade 
Lower grade 



Thicknesses, 
inches: 
Rough 
SIS 

S2S 

Widths, inches: 



Lengths, feet: 



Southern Pine Association, New 
Orleans, La. 

Georgia-Florida, Sawmill Asso- 
ciation, Jacksonville, Fla. 

No. 1 common 
No. 3 common 



1, m, iy2. 

Same as SIS. 

3 and up, in multiples of i, 
not over }/i inch scant on 8 
and under, 5^ on 9 or 10 and 
% on II and 12 or wider 



S. P. A. 4 to 24 in multiples 
of 2. G.— F. S. A. 8 to 20 
in multiples of 1. 

An average of 15 may be 
specified. 



North Carolina Pine Association, 
Norfolk, Va. 



No. 3 

Culls and merchantable red 
heart. 



1, 1J4, 1V2, m, 2. 
Vs, 13^, iH, iM, m. 

%, iM, iM. 13^, IM- 

Stocks— 6, 8, 10 and 12, Edge 
— random widths under 12 
except 6, 8, 10 inches, which 
are stocks. 4/4 edge is 3 
and wider, 5/4 to 8/4 edge 
is 4 and wider. 34 in width 
shall be allowed for dressing 
6 and under boards four 
sides, but 3^ shall be allowed 
for dressing boards wider 
than 6. 

8 to 16 in multiples of 2, not 
exceeding 5 per cent of 8 
foot. 

An average of 12 may be 
specified. 



APPENDIX 



145 



Spruce 



West Coast Lumber- 
men's Association, 
Seattle, Wash. 

Pacific Coast Lum- 
ber Inspection Bureau, 
Inc. 



Spruce Manufac- 
turers' Association (Not 
active although grad- 
ing rules are still used). 



Box grade 



Sitka spruce box 
lumber. 

The value and 
grade of this 
lumber is deter 
mined by its 
adaptability for 
the manufacture of 
ordinary packing 
boxes, ordinary 
sizes being defined 
as boxes not over 
20 inches in length 
nor more than 15 
inches in width. 
Wide boards or 
those of special 
widths will admit 
more defects than 
narrow or random 
widths. 

Grades — There are 
three recognized 
grades of box lum- 
ber, viz.: No. 1, 
No. 2 and No. 3. 

No. 1 — Generally 
sound, and con- 
tains from 75 per 
cent to 90 per cent 
of cuttings suit- 
able for boxes of 
ordinary size and 
quality, as re- 
ferred to above. 

In computing per- 
centages, cuttings 
of assorted sizes 
are used. Assort- 
ed sizes are defined 
as pieces running 
in widths from 6 
inches to 1 2 inches, 
and in lengths 
from 12 inches to 
20 inches. 



Appalachian spruce 
box. 

Large black knots, 
knots not sound 
in character, knot 
holes, heart 
checks or shakes, 
black sap and 
small amount of 
hard red wood ad- 
mitted. 

Wane or bark equal 
to half the thick- 
ness and one- 
fourth the length 
on the face or 
equal to 20 per 
cent of the piece 
on the back, ad- 
mitted. 

Season checks or 
splits equal to 14 
the length of the 
piece admitted. 

Pin worms and 
scattering grub 
holes admitted. 
This grade is de- 
signed for boxes 
and crating and 
some waste or bad 
material is al- 
lowed. 



New England 
spruce. 

No standard grad- 
ing rules are in 
effect. The 
lumber is graded 
principally accord- 
ing to verbal 
understanding be- 
tween buyer and 
seller or according 
to local specifica- 
tions which have 
been in use for a 
number of years. 

Massachusetts 
State Law for the 
inspection of 
Lumber. 

Box boards, waney 
edged box boards, 
pine, bass wood, 
poplar and spruce 
are inspected as 
good and culls. 

Good includes all 
sound lumber so 
free from black, 
mouldy, or rotten 
sap, rot, worm 
holes and bad 
shakes, that not 
less than % of the 
entire piece (as a 
whole) can be used 
without waste. 

Culls include a\ 
lumber not good 
enough for the 
above grade. 

The Navy Depart- 
ment has the fol- 
lowing rule for 
New England 
spruce (39Slb.): 



146 



WOODEN BOX AND CRATE CONSTRUCTION 



Spruce — Continued 



ITEM 



Higher grade 

Lower grade 

Thicknesses, 
inches: 
Rough 
SlSorS2S 

Widths, inches: 
Rough 
S2E 

Length, feet 



West Coast Lumber- 
men's Association, 
Seattle, Wash. 

Pacific Coast Lum- 
ber Inspection Bureau. 
Inc. 



Spruce Manufac- 

turers' Association (Not 
active although grad- 
ing rules are still used). 



Sitka spruce box 
lumber — Cont'd. 

No. 2 — Generally 
similar in charac- 
ter to No. 1, con- 
taining 60 per cent 
to 75 per cent of 
box cutting. 

No. 3— All lumber 
below the grade of 
No. 2 and contain 
ing 40 per cent to 
60 per cent of box 
cuttings. 



No. 1 common. 
None. 






4,6,8, 10,12. 
3H, 5M, 7H, 9K, 
UK- 

6 to 20 in multiples 
of 2. 



New England 
spruce — Cont'd. 

Box: (a) Sizes: — 
Lengths to be ran- 
dom 6 feet and up. 
Widths to be 4 
inches and up as 
specified. Thick- 
nesses as specified, 
(b) Defects allow- 
ed — This grade 
will admit the fol- 
lowing: Large 
branch and black 
knots, knot holes, 
worm holes, 
stained sap, and a 
reasonable amount 
of hard red rot. 
Wane not exceed- 
ing one-half the 
thickness of piece 
and extending full 
length on one edge 
only or a propor- 
tional amount on 
two edges. Shakes, 
splits or checks 
equal to }4 length 
of piece. 



Merchantable. 
Mill culls. 



I.IM, 13^,2. 



4 and wider. 
3%, 5^, 7ys. 9K, 
IIM. 

6 and longer. Not 
over 5 per cent 6 
feet. 



APPENDIX 



147 



Red and sap gum 



ITEM 



National Hardwood Lumber Association, Chicago, 111. 

American Hardwood Manufacturers' Association, Memphis, Tenn. 



Box grades 



Higher grade 
Lower grade 
Thicknesses 
Widths, inches 
^Lengths, feet 



No. 2 common red and sap gum. 

Pieces 3 to 7 inches wide, 4 to 10 feet long must work 50 
per cent clear face or sound sap in not over three cuttings; 
pieces 3 to 7 inches wide, 11 feet and longer must work 50 
per cent clear red face or sound sap in not over four cut- 
tings; pieces 8 inches and over wide, 4 to 9 feet long must 
work 50 per cent clear red face or sound sap in not over 
three cuttings; pieces 8 inches and over wide, 10 to 13 
feet long must work 50 per cent clear red face or sound 
sap in not over four cuttings; pieces 8 inches and over 
wide, 14 feet and over long must work 50 per cent clear 
red face of sound sap in not over five cuttings. No cut- 
ting to be considered which is less than 3 inches wide by 
2 feet long. Sound discolored sap is no defect in any 
grade of sap gum. 

No. 1 common. 

No. 3 common. 

See Table 9. 

3 and over in random widths, average of 9 may be specified. 

4 and over, but not more than 10 per cent 4 and 5 foot 
lengths admitted in this grade. Average of 11 may be 
specified. 



148 



WOODEN BOX AND CRATE CONSTRUCTION 



Western yellow pine 



ITEM 



Western Pine Manufacturers' 
Association, Spokane, Wash. 



California White and Sugar Pine 
Manufacturers' Association. 



Box grade 



Higher grade 

Lower grade 

Thicknesses, • 
inches: 
Rough 
SIS or S2S 

Widths, inches 
Length, feet 



"Western white pine." 
No. 4 common. 

1. The defects common to 
this grade are much the same 
as those in No. 3 but greater. 

2. The most common serious 
defects are knot holes, and 
either red rot, or its equiva- 
lent in heavy massed pitch. 
Other types are: extremely 
coarse knotted, or waney, 
or badly split, or badly 
checked pieces, or pieces 
with excessive heart shake. 

3. This grade especially 
meets the demands of the 
box manufacturer for a soft, 
easily-worked pine in a grade 
that yields well in cut-up box 
product. 



No. 3 common. 
No. 5 common. 



1, IM, 1^, 2. 

II, ivs, iVs, m- 

4 and wider. If S2E, 
scant. 



"California white pine." 
No. 3 common and fencing. 

The general appearance of 
this grade of lumber is coarse. 
It admits large, loose or 
unsound knots, an occasional 
knot hole, some shake, worm 
holes, some red rot, any 
amount of stained sap, but 
not a serious combination of 
these defects in any one 
piece. 

A grade similai" to No. 3 com- 
mon is sometimes sold as 
No. 1 Box in California. 

No. 4 common and strips. 

The predominating defects 
characterizing this grade are 
red rot, pitch, and stain. 
Other types are pieces show- 
ing numerous large worm 
holes, or pieces that are ex- 
tremely coarse knotted, 
waney, shaky, or badly split. 

A grade similar to No. 4 com- 
mon is sometimes sold as 
No. 2 box. 

No. 3 common. 

None. 



1, IM, IH, 2. 

4 and wider. 



6 and longer. 



6 and longer. 



APPENDIX 



149 



Cottonwood 



ITEM 



National Hardwood Lumber Association 
American Hardwood Manufacturers' Association 



Box grade 



Higher grade 

Lower grade 

Thicknesses 

Widths, inches 
Lengths, feet 



No. 2 common. 

Pieces 3 to 7 inches wide, 4 to 10 feet long must work 50 
per cent sound in not over three cuttings; pieces 3 to 7 
inches wide, 11 feet and longer must work 50 per cent 
sound in not over four cuttings; pieces 8 inches and over 
wide, 4 to 9 feet long must work 50 per cent sound in not 
over three cuttings; pieces 8 inches and over wide, 10 to 
13 feet long must work 50 per cent sound in not over four 
cuttings; pieces 8 inches and over wide, 14 feet and over 
long must work 50 per cent sound in not over five cuttings. 

No cutting to be considered which is less than 3 inches 
wide by 2 feet long. 

No. 1 common. 

No. 3 common. 

See Table 9. 

3 and over, average of 9 may be specified. 4 and over, not 
to exceed 10 per cent of 4 and 5 foot lengths. Average of 
11 may be specified. 



150 



WOODEN BOX AND CRATE CONSTRUCTION 



ITEM 



Box grades 



Higher grade 
Lower grade 
Thicknesses 
Width, inches 
Lengths, feet 



1 



Yellow poplar 



National Hardwood Lumber Association 
American Hardwood Manufacturers' Association 



No. 2-B common. 

No. 2 common is divided into No. 2-A common and No. 2-B 
common, but unless otherwise specified is to be considered 
as a combined grade. 

Sound discolored sap is no defect in this grade. 

No. 2-B common — pieces 3 to 7 inches wide, 4 to 10 feet 
long must work 50 per cent sound in not over three cut- 
tings; pieces 3 to 7 inches wide, 11 feet and longer must 
work 50 per cent sound in not over four cuttings; pieces 
8 inches and over wide, 4 to 9 feet long must work 50 per 
cent sound in not over three cuttings; pieces 8 inches and 
over wide, 10 to 13 feet long must work 50 per cent sound 
in not over four cuttings; pieces 8 inches and over wide, 
14 feet and over long must work 50 per cent sound in not 
over five cuttings. 

No cutting to be considered which is less than 3 inches wide 
by 2 feet long. 

No. 2-A common and No. 1 common. 

No. 3 common. 

See Table 9. 

3 and over, average of 9 may be specified. 

4 and over, not more than 10 per cent of 4- and 5-foot 
lengths. Average of 9 may be specified. 



APPENDIX 



151 



Hemlock 



ITEM 



Box grade 



West Coast Lumber- 
men's Association 



Northern Hemlock 
and Hardwood Manu- 
facturers' Association 



No. 2 common. 



Must be free from 
rot. Admits large, 
coarse knots ap- 
proximately 2 
inches in diameter 
in 4-inch and 6- 
inch stock, 2 3/^ 
inches in 8 and 10- 
inch, and 3^ the 
width of the piece 
in 12-inch and 
wider, spike knots, 
any amount of 
solid heart or sap 
stain, a limited 
number of well 
scattered worm 
holes, solid pitch 
or pitch pockets, 
small amount of 
fine shake, wane 2 
inches wide, if it 
does not extend 
into the opposite 
face. A serious 
combination of 
above defects in 
any one piece is 
not permitted. A 
board may have 
one large knot 
hole, provided the 
piece is otherwise 
as good as No. 1 
common. 



Box and crating 
inch and dimen- 
sion. 

Stock that will cut 
at least 50 per 
cent of firm, useful 
box and crating 
stock. Includes 
No. 3 hemlock, 
4/4 and 8/4, 2 
inches and wider, 
4 feet and longer, 
and admits defects 
of the following 
character: 

Soft rot, open shake, 
coarse loose knots 
and knot holes, or 
any other defect 
that is character- 
istic of hemlock, 
that will weaken 
stock to the ex- 
tent of barring its 
use for dimension 
purposes. 

This grade must be 
based on the per- 
centage of useful 
material that each 
piece contains, as 
it is impossible to 
describe the de 
fects which this 
stock contains. 



Eastern States Hem- 
lock 



Spruce Manufac- 
turers' Association 
rules sometimes 
used in West Vir- 
ginia and North 
Carolina. In 
Pen nsy 1 va nia , 
New York, and 
New England 
local rules for 
"Box" followed. 



152 



WOODEN BOX AND CRATE CONSTRUCTION 



Hemlock — Continued 



ITEM 



Higher grade 

Lower grade 

Thicknesses, 
inches: 
Rough 
SIS 
S2S 

Widths, inches 
SIE 

S2E 

Lengths, feet. 



West Coast Lumber- 
men's Association 



No. 1 common. 
No. 3 common. 



1, iM, m, 2. 

M.iM.iM.lM- 

Same as SIS. 



4, 6, 8, 10, 12. 



^2, iYa. 



iiM 

Same as SlE. 
10 to 20. 



, 9M. 



Northern Hemlock 
and Hardwood Manu- 
facturers' Association 



Select No. 3 com- 
mon. 

No. 4 common. 



11, IH- 
ii, iVs- 

2, 4, 6, 8, 10, 12. 
}4, to ^ scant. 

% scant. 

4 to 20 in multiples 
of 2. 



Eastern States Hem- 
lock 



APPENDIX 



153 



Soft maple and soft elm 



ITEM 



National Hardwood Lumber Association 
American Hardwood Manufacturers' Association 



Box grade 



Higher grade 
Lower grade 
Thicknesses 
Widths, inches 
Lengths, feet 



No. 2 common. 

Pieces 3 to 7 inches wide, 4 to 10 feet long must work 50 
per cent sound in not over three cuttings; pieces 3 to 7 
inches wide, 11 feet and over long must work 50 per cent 
sound in not over four cuttings; pieces 8 inches and over 
wide, 4 to 9 feet long must work 50 per cent sound in not 
over three cuttings; pieces 8 inches and over wide, 10 to 13 
feet long must work 50 per cent sound in not over four 
cuttings; pieces 8 inches and over wide, 14 feet and over 
long must work 50 per cent sound in not over five cuttings. 

No cutting to be considered which is less than 3 inches 
wide by 2 feet long. 

No. 1 common. 

No. 3 common. 

See Table 9. 

3 and over, average of 7 may be specified. 

4 and over, not over 10 per cent 4- and 5-foot lengths. 
Average of 11 may be specified. 



154 



WOODEN BOX AND CRATE CONSTRUCTION 



Birch 



ITEM 



National Hardwood Lumber Association 
American Hardwood Manufacturers' Association 



Box grades 



Higher grade 
Lower grade 
Thicknesses 
Widths, inches 
Lengths, feet 



No. 2 common. 

Pieces 3 to 7 inches wide, 4 to 10 feet long must work 50 
per cent clear face in not over three cuttings; pieces 3 to 7 
inches wide, 11 feet and over long must work 50 per cent 
clear face in not over four cuttings; pieces 8 inches and 
over wide, 4 to 9 feet long must work 50 per cent clear 
face in not over three cuttings; pieces 8 inches and over 
wide, 10 to 13 feet long must work 50 per cent clear face 
in not over four cuttings; pieces 8 inches and over wide, 
14 feet and over long must work 50 per cent clear face in 
not over five cuttings. 

No cutting to be considered which is less than 3 inches 
wide by 2 feet long. 

No. 1 common. 

No. 3 common. 

See Table 9. 

3 and over, average of 7 may be specified. 

4 and over, not over 10 per cent 4- and 5-foot lengths. 
Average of 11 may be specified. 



APPENDIX 



155 



Basswood 



ITEM 



National Hardwood Lumber Association 
American Hardwood Manufacturers' Association 



Box grades 



Higher grade 
Lower grade 
Thicknesses 

Widths, inches 
Lengths, feet 



No. 2 common. 

Pieces 3 to 7 inches wide, 4 to 10 feet long must work 50 
per cent sound in not over three cuttings; pieces 3 to 7 
inches wide, 11 feet and over long must work 50 per cent 
sound in not over four cuttings; pieces 6 inches and over 
wide, 4 to 9 feet long must work 50 per cent sound in not 
over three cuttings; pieces 8 inches and over wide, 10 to 13 
feet long must work 50 per cent sound in not over four 
cuttings; pieces 8 inches and over wide, 14 feet and over 
long must work 50 per cent sound in not over five cuttings. 

No cutting to be considered which is less than 3 inches 
wide by 2 feet long. 

No. 1 common. 

No. 3 common. 

See Table 9. 

3 and over. Average of 9 may be specified. 

4 and over, not over 10 per cent 4- and 5-foot lengths. 
Average of 11 may be specified. 



156 



WOODEN BOX AND CRATE CONSTRUCTION 



Beech 



ITEM 



National Hardwood Lumber Association 
American Hardwood Manufacturers' Association 



Box grades 



Higher grade 
Lower grade 
Thicknesses 
Widths, inches 
Lengths, feet 



No. 2 common. 

Pieces 3 to 7 inches wide, 4 to 10 feet long must work 50 
per cent clear face in not over three cuttings; pieces 3 to 
7 inches wide, 11 feet and over long must work 50 per 
cent clear face in not over four cuttings; pieces 8 inches 
and over wide, 4 to 9 feet long must work 50 per cent clear 
face in not over three cuttings; pieces 8 inches and over 
wide, 10 to 13 feet long must work 50 per cent clear face 
in not over four cuttings; pieces 8 inches and over wide, 
14 feet and over long must work 50 per cent clear face in 
not over five cuttings. 

No cutting to be considered which is less than 3 inches 
wide by 2 feet long. 

Wormy beech. 

Shall be graded according to the rule for beech No. 2 com- 
mon and better, with the exception that pin worm holes 
shall not be considered a defect. 

No. 1 common. 

No. 3 common. 

See Table 9. 

3 and over. Average of 7 may be specified. 

4 and over, not over 10 per cent 4- and 5-foot lengths. 
Average of 11 may be specified. 



APPENDIX 



157 



Tupelo and black gum 



National Hardwood LumberTAssociation 

American Hardwood Manufacturers' Association 

Southern Cypress Manufacturers' Association, New Orleans, La. 



Box grades 



Higher grade 
Lower grade 
Thicknesses 
Widths, inches 
Lengths, feet 



No. 2 common. 

There is no restriction as to heart in No. 2 common tupelo. 

Sound discolored sap is no defect. 

Pieces 3 to 7 inches wide, 4 to 10 feet long must work 50 
per cent sound in not over three cuttings; pieces 3 to 7 
inches wide, 11 feet and longer must work 50 per cent 
sound in not over four cuttings; pieces 8 inches and over 
wide, 4 to 9 feet long must work 50 per cent sound in not 
over three cuttings; pieces 8 inches and over wide, 10 to 
13 feet long must work 50 per cent sound in not over four 
cuttings; pieces 8 inches and over wide, 14 feet and over 
long must work 50 per cent sound in not over five cuttings. 

No cutting to be considered which is less than 3 inches 
wide by 2 feet long. 

No. 1 common. 

No. 3 common. 

See Table 9. 

3 and over. Average of 7 may be specified. 

4 and over, not over 10 per cent 4- and 5-foot lengths. 
Average of 10 may be specified. 



158 



WOODEN BOX AND CRATE CONSTRUCTION 



Oak (pleiin, red, or white) 



ITEM 



National Hardwood Lumber Association 
American Hardwood Manufacturers' Association 



Box grade 



Higher grade 
Lower grade 
Thicknesses 
Widths, inches 
Lengths, feet 



No. 2 common. 

Pieces 3 to 7 inches wide, 4 to 10 feet long must work 50 
per cent clear face in not over three cuttings; pieces 3 to 
7 inches wide, 11 feet and longer must work 50 per cent 
clear face in not over four cuttings; pieces 8 inches and 
over wide, 4 to 9 feet long must work 50 per cent clear 
face in not over three cuttings; pieces 8 inches and over 
wide, 10 to 13 feet long must work 50 per cent clear face 
in not over four cuttings; pieces 8 inches and over wide, 
14 feet and over long must work 50 per cent clear face in 
not over five cuttings. 

No cutting to be considered which is less than 3 inches 
wide by 2 feet long. 

No. 1 common. 

No. 3 common 

See Table 9. 

3 and over. Average of 7 may be specified. 

4 and over, not to exceed 10 per cent of 4- and 5-foot 
lengths. Average of 10 may be specified. 



APPENDIX 



159 



Balsam fir 



ITEM 



Northern Pine Manufacturers' 
Association ' 



May be purchased with white 
pine. 



New England balsam fir 



Usually sold with spruce. 



160 



WOODEN BOX AND CRATE CONSTRUCTION 



Cypress 



ITEM 



National 
Association 



Hardwood Lumber 



Southern Cypress Manufactur- 
ers' Association 

American Hardwood Manufac- 
turers' Association 



Box grades 



Higher grade 

Lower grade 

Thicknesses, 
inches: 
Rough 
SIS 

S2S 

Widthg, inches 

Length, feet 



No. 1 boxing. 

Must work 66% per cent in 
cuttings containing not less 
than 72 square inches. No 
cutting considered which is 
less than 18 inches long or 
less than 3 inches wide. 

Each cutting may contain 
sound stain, pin worm holes, 
unsound knots and peck that 
do not extend through the 
piece, season checks, and 
other defects that do not 
prevent the use of the cut 
ting for boxing purposes. 

No. 2 boxing. 

This grade may contain all 
lumber not admitted in No. 
1 boxing, but each piece must 
work at least 50 per cent in 
the same size cuttings de- 
scribed in No. 1 boxing. 

No. 2 common. 

Peck. 



Same as for hardwoods. 
See Table 9. 



Random widths 3 and over. 
Average of 7 may be specified. 



No. 1 boxing, 6 and over. 
No. 2 boxing, 4 and over 

Equal proportions may be 

specified. 



Box. 

Each piece must contain 66% 
per cent or more of sound 
cuttings, no single cutting to 
contain less than 72 square 
inches. No piece of cutting 
may be shorter than 2 feet 
or narrower than 3 inches. 
Sound cuttings will admit all 
the defects allowed in No. 1 
common. The waste ma- 
terial may be thin or abso- 
lutely worthless. 



No. 2 common. 
Peck. 



1, iH, m, 2. 

%, 1^, 1%, IH. 

Same as SIS. 

Random widths 3 and wider. 
Average of 7 may be specified 
SIE, Vs off; S2E J^ off. 

6 to 20. Average of 12 may 
be specified. 



APPENDIX 



161 



Chestnut 



ITEM 



Box grades 



Higher grade 
Lower grade 
Thicknesses 
Widths, inches 

Lengths, feet 



National Hardwood Lumber Association 
American Hardwood Manufacturers' Association 



No. 2 common. 

Pieces 3 to 7 inches wide, 4 to 10 feet long must work 50 
per cent sound in not over three cuttings; pieces 3 to 7 
inches wide, 11 feet and over long must work 50 per cent 
sound in not over four cuttings; pieces 8 inches and over 
wide, 4 to 9 feet long must work 50 per cent sound in not 
over three cuttings; pieces 8 inches and over wide, 10 to 
13 feet long must work 50 per cent sound in not over four 
cuttings; pieces 8 inches and over wide, 14 feet and over 
long must work 50 per cent sound in not over five cuttings. 

No cutting to be considered which is less than 3 inches 
wide by 2 feet long. 

Sound Wormy 

Worm holes admitted in this grade without limit. 

No piece shall contain heart to exceed % its length in the 
aggregate. 

Pieces 4 inches wide, 6 and 7 feet long must be sound; 8 to 
11 feet long must work 66% per cent sound in not over 
two pieces; 12 feet and over long must work 66% per cent 
sound in not over three pieces. No piece of cutting to be 
less than 2 feet long by the full width of the piece. 

Pieces 5 inches and over wide, 6 to 11 feet long must work 
66% per cent sound in not over two pieces; 12 feet and 
over long must work 66% per cent sound in not over 
three pieces. 

No piece of cutting considered "which is less than 4 inches 
wide by 2 feet long or 3 inches wide by 3 feet long. 

No. 1 common. 

No. 3 common. 

See Table 9. 



No. 2 — 3 and over. Sound wormy, 4 and over, 
of 8 may be specified. 



Average 



No. 2 — 4 and over, not to exceed 10 per cent of 4- and 

5-foot lengths. 
Sound wormy, 6 and over, not to exceed 10 per cent of 

6- and 7-foot lengths. Average of 11 may be specified. 



Sugar pine 

Same as western yellow pine (California white pine) on page 148 under 
rules of California White and Sus;ar Pine Association. 



162 WOODEN BOX AND CRATE CONSTRUCTION 



Plate I — Defects recognized in the commercial grading of lumber. 



w 



Pin knots 



APPENDIX 




Slanaard kiujl 



Large ki 



163 

Platk 1 



9 



l.iiLa>L'il knut 



L'' 


rith knot 




1 



'# 




Rotten knot 



Spike knot 




•Heart' 
Pith 




Shake 



Checks 



Pitch pocket 
Upper: Edge-grain 

Pitch pocket 
Lower: Flat-grain 



Pitch streal. 




I— — — giW fil'i 



aMAl^aa^Aaa 




Stained sap 



Water stain 



Mineral streaks 



Gum spots 




Bird pecks 



Rut 



Shot-worm holes 
Grub-worm holes 



KalliU4 [1111 iiuk 
Knot hole 




Wane 



Loosened grain 



Insufficient thickness 
Chipped grain 



Method of measuring 

knots 

"A" is the effective 

diameter 



164 



WOODEN BOX AND CRATE CONSTRUCTION 

SUW ^"^^'^ " 



Fig. 1 
White Oak 

A hardwood show 
ing- V, vessels oi 
pores; TY, tyloses 
in a vessel; P, par- 
enchyma cells. The 
dark areas, F, wood 
fibers; MR, medul- 
lary ray. 




Fig. 2 

Shortleaf Pine 

A c o n i f erous 
wood showing: T, 
tracheids, which 
comprise the bulk 
of the wood; Kl), 
resin duct; MR, 
medullary ray. 



liiii^D 



APPENDIX 165 



Plate II — Cubes of wood magnified about 25 diameters. 
Fig. 1— White oak. 
Fig. 2 — Shortleaf pine. 

In each cube the top view represents the transverse or end sur- 
face, the left view the radial or "quartered" surface, and the right 
view the tangential or plain-sawed surface. (SPW) springwood; 
(SUW) summerwood. 

The medullary rays are continuous from the starting point to the 
bark, and the vessels are continuous longitudinally, although the 
illustrations show them interrupted. 



166 WOODEN BOX AND CRATE CONSTRUCTION 



Plate III — Styles of wooden boxes, nailed aiid lock-corner construction. 



APPENDIX 



167 
Plate III 



Alternate forms 

of Cleah. 




168 WOODEN BOX AND CRATE CONSTRUCTION 



Plate IV — Special styles of boxes. 

Figs. 1 and 3 — Boxes made for easy opening. 

Fig. 2 — An accessible box (cover screwed on and sealed with wax). 
Fig. 4 — Modified Style 2 box adapted to be closed without nailing. 
Fig. 5 — Modified Style 4 box adapted to be closed without nailing. 



APPENDIX 



169 



Plate IV 




170 



WOODEN BOX AND CRATE CONSTRUCTION 



Plate V — Strapped boxes. 

Fig. 1 — Reinforced battens. 

Fig. 2 — End-opening box, cover held only by strapping. 

Fig. 3 — Double corner nails to keep the straps in position if shrinkage 

occurs. 
Figs. 4 and 5 — Common methods of box strapping. 



APPENDIX 



171 



Plate V 




172 



WOODEN BOX AND CRATE CONSTRUCTION 



Plate VI — Types of handles. 

Fig. 1 — Handhold for boxes in which the opening is not objectionable. 
Fig. 2 — Section of a box end with handhold formed by beveling the 

edge of cleat. 
Fig. 3 — Handhold for boxes of medium weight that need to be 

handled with care. 
Fig. 4 — Method of attaching rope handles. 

Right — Outside end of box. 

Left — Reverse side of cleats. . 
Fig. 5 — Method of attaching webbing handles. 

Upper — Outside face of end. 

Lower — Inside face of end. 
Fig. 6 — Another method of attaching webbing handles. 

Left — Outside face of end. 

Right — Inside face of end. 



APPENDIX 




174 WOODEN BOX AND CRATE CONSTRUCTION 



Plate VII^ — Different types of corner construction. 
Fig. 1 — Details of dovetail corner. 
Fig. 2 — Dovetail box corner. 
Fig. 3 — Test specimens for determining holding power of nails parallel 

virith and at an angle to grain. 
Fig. 4 — Joints for 4-one box cleats. 

Upper — Mortise and tenon. 

Lower — Step mitre. 



APPENDIX 



175 



Plate VII 




Fig. 1 



■ 1 ■ i 

1 i \ 

1 1. 1 


."'^fl 


ii ! 


1- -\'i 


i" • 


,'f 


\ ■ 


1 


\ 


1 




Fig. 3 







Fig. 2 



Fig. 4 



176 WOODEN BOX AND CRATE CONSTRUCTION 



Plate VIII — Wirebound boxes. 

Fig. 1 — Fassnacht box — note method of joining the wires at the 

corners. 
Fjg. 2 — Method of reinforcing battens, (c) Regular cleats with mortised 

and tenoned joints, (b) Battens, (n) Cement-coated (7d) nails. 
Fig. 3 — "4-one" wirebound box closed for shipment. Note position 

and character of twists for uniting the binding wires. 
Fig. a — The outer surface of a mat for a "4-one" box. 
Fig. 5 — "4-one" box with inside liners or corner cleats. 
Fig. 6 — "4-one" wirebound box assembled. 



APPENDIX 



\77 



Pl.ATK VI 11 




178 



WOODEN BOX AND CRATE CONSTRUCTION 



Plate IX — Types of commercial boxes. 

Fig. 1 — Phonograph box made of plywood fastened to a frame. 

Fig. 2 — Egg crate with sides, top, and bottom made of rotary- cut 

veneer. 
Fig. 3 — Apple box. 
Fig. a — Orange case. 
Fig. 5 — Upright piano box. 



APPENDIX 



179 



Plate IX 




Fig. 4 



Fig. 5 



180 WOODEN BOX AND- CRATE CONSTRUCTION 



Plate X — ^Types of plywood or veneer panel boxes. 

Fig. 1 — This box corresponds in some points of construction with 

Style 3 of nailed box. 
Fig. 2 — Corresponds in some respects with hardware type (Fig. 3) 

shown in Plate XIV. 
Fig. 3 — Corresponds most closely to Style 2 of nailed box. 
Fig. 4 — This box has double number of cleats of box shown in Fig. 2 

but is otherwise similar in construction. 



I 



AI'riiNIJIX 



181 



Plate X 




182 WOODEN BOX AND CRATE CONSTRUCTION 



Plate XI — Three-way crate corners. 

Fig. 1 — Three-way crate corner made of 25^ by 3^ inch stock. 

Fig. 2 — Three-way crate corner made of 2 by 6 inch stock. 

Fig. 3 — Three-way crate corner made of 2^/s by 3-)4 inch stock. 

Fig. 4 — Method of cutting and naiHng a diagonal brace. 

Fig. 5 — A common style of crate corner. 

Fig. 6 — A style of crate corner consisting of the corner as shown in 

Fig. 5 with one double member. 
Fig. 7 — One method of reinforcing a crate corner. 



I 



APPENDIX 



m 



Plate XI 




184 WOODEN BOX AND CRATE CONSTRUCTION 



Plate XII — Various arrangements of crate members at three-way corner. 



APPENDIX 



185 



Plate XII 




186 



WOODEN BOX AND CRATE CONSTRUCTION 



Plate XIII — Crates with special features. 

Fig. 1 — Several sets of cross-bracing and cross-members used to in- 
crease rigidity and bending strength. 

Fig. 2 — The scabbing shown inside the vertical members extends to the 
outer edges of the top and bottom horizontal crate members. 

Fig. 3 — Framework of crate to which all other parts are fastened. 

Fig. 4 — Crate with 3-vvay corner construction showing cross-bracing, 
diagonal bracing, and extra pieces to strengthen the skids which 
support the vertical members. 



APPENDIX 



187 



Pi. ATI- XIII 




188 WOODEN BOX AND CRATE CONSTRUCTION 



Plate XIV — Method of numbering faces of test boxes and crates for 
convenience in recording data and location of failures. 

Figs. 1 and 2 — Crate numbering system. 
Figs. 3 and 4 — Box numbering system. 



APPENDIX 



189 



Plate XIV 




190 



'WOODEN BOX AND CRATE CONSTRUCTION 



Plate XV — Different kinds of joints and fasteners. 

Fig. 1 — Use of corrugated fasteners. 

Fig. 2 — Different types of corrugated fasteners. 

Fig. 3 — Dovetail joint. 

Fig. 4 — Coil of corrugated fastening material. 

Fig. 5 — Lock-corner joint. 

Fig. 6 — Lap joint. 



APPENDIX 



191 



Plate XV 




192 



WOODEN BOX AND CRATE CONSTRUCTION 



Plate XVI — Hardwoods with pores. 

Ring-porous hardwoods, figures 1-9 inclusive, 
Summerwood with radial figure, figures 1-3. 
Summerwood with tangential figure, figures 4-8. 
Summerwood without special figure, figure 9. 

Diffuse-porous hardwoods, figures 10-12 inclusive. 
Pores easily visible to naked eye, figure 10. 
Pores barely visible to naked eye, figures 11-12. 



APPENDIX 



193 

Plate XVI 




I' lo. i — A red oak. Fig. 2 — .\ white oak. 




Fig. 4 — Wliite elm. 



Fig. 5 — Cork or rock elm. Fir;. 6 — Slippery elm. 




Fig. 7 — Hackberry. 



Fig. 8 — A white ash. 



. "■'"■'^"•■i -"*--■ niOAiJiUlili I", ifi 

Fig. 9— Black a.sh. 







Fig. 10 — Butternut 



Fig. 11— Birch. 



Fig. 12 — Cottonwood. 



194 , WOODEN BOX AND CRATE CONSTRUCTION 

Plate XVII 




Fig. 1 — Yellow poplar. 



Fig. 2 — Black gum. 



Fig. 3 — Aspen, or "pop- 
ple." 




Fig. 4 — Buckeye. 




Fig. 5 — Ripple marks 
on tangential surface 
as in buckeye. 




Fig. 9 — Soft maple. 



Hard maple 



Fig. 11 — Basswood. 



APPENDIX 195 



Plate XVII — Diffuse-porous hardwoods. 

The pores in these woods are not readily visible to the naked eye. 
The rays vary in size : 
Conspicuous in figures 6 and 7 

Not conspicuous but visible, figures 1, 8, 9, 10 and 11. 
Not distinctly visible figures 2, 3, 4. 



196 



WOODEN BOX AND CRATE CONSTRUCTION 



Plate XVIII — Softwoods, conifers, or woods without pores or vessels. 

Woods' without resin ducts, figures 1-6. 
Woods with resin ducts, figures 7-12. 



APPENDIX 



197 
Plate XVIII 




Fig. 1 — Pon iJriurd 
cedar. 



Fig. 2 — Western red 
cedar. 




Fig. 3 Cyprt. 




I'^iG. 4 — True fir. 



Fig. 5 — Hemlock. 



Fig. 6 — Redwood. 




Fig. 7 — White pine. 



Fig. 8 — Western yel- 
low pine. 



Fig. 9 — SuiUhcrn ycl 
low pine. 




Fig. 10— Douglas hr 



I'lG. 12— Spruce. 



198 WOODEN BOX AND CRATE CONSTRUCTION 



Plate XIX 





4 ■■ 



iiiKh 



tr •^ 




Fig. 1 — Sitka spruce 



Fig. 2 — Douglas fir. 



APPENDIX 199 



Plate XIX — Split tangential surfaces of Sitka spruce and Douglas fir. 

Note the "pocked" or "dimpled" appearance of the spruce, not found in 
Douglas fir. This characteristic is most pronounced in Sitka 
spruce with narrow rings, and is almost entirely ahsent in very 
wide-ringed material. 



INDEX 



A 

Air-drying of lumber. As decay 
preventive, 32, 36 

time necessary for, 36 
Allowance for shrinkage, 17 
Alpine fir. Identification, 136 
Annealed strapping, 60 
Annual rings, 110 
Appalachian spruce. Rules for 

grading, 145 
Arborvitae. Structure, 122 
Army ordnance boxes, 43 
Ash. Identification, 127 

structure, 119 

sec also Black ash ; Green ash ; 
Pumpkin ash ; White ash 
Aspen, sec Popple 
Assembling of wirebound boxes, 105 

with detached tops, 107 

with wedgelock ends, 107 
Association grading rules, 11 
Availability of box lumber, 1, 41 

B 

Balanced construction, 43 

how determined, 87 

relation to nailing qualities of 
wood, 51, 53 

spacing of nails in, 55 
Bald cypress. Identification. 135 
Balsam fir. Identification, 136 

rules for grading, 159 
Barbed nails, 55 
Basswood. Identification, 131 

rules for grading, 155 

structure, 121 
Battens. In crates, 81 

in wirebound boxes, 68, 107 

use in strapping, 61 
Beech. Identification, 130 

rules for grading, 156 

structure, 120 
Binding rods in crates, 84 
Binding wire for wirebound boxes, 

105 
Birch. Identification, 128 

rules for grading, 154 

structure, 121 
Bird pecks, 10 

200 



Black ash. Identification, 127 

structure, 119 
Black gum. Identification, 131 

rules for grading, 157 

structure, 122 
Blemishes in lumber, 8 
Blue stain, 31, 110 
Bolting qualities of wood, 81 
Bolts. Carriage, 83 

machine, 84 

use in crates, 83 
Bored holes for nails. Efifect, 83 

for lag screws, 84 
Bow, 10 
Box design, 40, balance in 43 

characteristic of various styles, 
64 

defined, 40 

factors determining size, 72 

factors determining strength re- 
quired, 70 

factors influencing details, 40 

limitations by traffic rules, 74, 85 

of boxes with detached tops, 107 

of hinged boxes, 62 

of wirebound boxes, 103 

one-piece parts, 44 

relation to available equipment, 
42 

relation to strapping, 61 

relation to wood groups, 103 

special constructions, 74 

with wedgelock ends, 105 
Boxes. Salvage value, 1 

second hand, 2 
Box nails, 53, 101 
Box styles, 42 

Box lumber, sec Lumber ; Woods. 
Braces. Fitting and fastening, 80 

internal, 84 

use on long crates, 79 
Buckeye. Structure, 122 

see also Yellow buckeye 
Butt joint, 44 
Butternut. Identification, 128 

structure, 120 

C 

California white pine, see Yellow 
pine 



INDEX 



201 



Canned foods boxes. Specifications, 

103 
Carolina pine, sec Southern yellow- 
pine. 
Carriage lx)lts in crating, 83, 84 
Case hardening of lumber, 25, 31 
Cedar. Identification, 132 
structure, 122 

sec also Northern white cedar ; 
Port Orford cedar ; Red 
cedar ; Western red cedar 
Cells in boxes, 74 
Cement-coated nails, 55, 101 
use in wi rebound boxes, 106 

Checks. 9, 25, 31 

effect on strength of box, 50 

use of corrugated fasteners, 45, 
50 
Chestnut. Identification, 127 

rules for grading, 161 

structure, 118 
Classifications, Freight, limiting de- 
sign, 74 
Cleats. On standard styles, 65 

on wirebound boxes, 68, 105 
Clinching of nails, 56 
Closing wirebound boxes, 106, 107 
Collapse of wood cells in drying, 23, 

31 
Color of wood, 25, 109 
Compartment boxes, 24 
Compression-cornerwise test, 96 
Compression-on-faces test, 96 
Compression-on-an-edge test, 92 
Compression strength of wood, 26 

in crates, 78 
Conifers. Description, 132 

identification, 122 

structure, 114 
Construction. Width of pieces, 101 

of wirebound boxes, 104 
Contents. Determining size of 
boxes, 73 

effect on required strength, 70 

nesting, disassembling or knock- 
ing down, 73 

protection from the elements, 81 

protection of fragile contents, 
74 
Cork elm, sec Rock elm 
Corner irons, 62 

Corner construction of boxes, 66 
Corner construction of crates, 77 
Corrugated fasteners, 44, 45, 50, 101 



Cost. Air drying, 37 

of boxes in relation to use of re- 
inforcements, 45 

of box lumber, 1 

of box lumber in relation to sal- 
vage, 42 

of factory operation, 42 

of kiln-drying, 37 
Cotton gum. Identification 131 
Cottonwood. Identification, 129 

rules for grading, 149 

structure, 120 
Crates. Bracing, 79 

corner construction, 77 

design, 77 

effect of physical properties of 
wood, 81 

factors determining strength 
required, 85 

factors affecting strength, 77 

factors influencing size, 86 

fastenings, 82 

frame members, 78 

reinforcements, 82 

scabbing, 80 

sheathing, 81 

skids, 79 
Crook, 10 

Cross bracing in crates. Rules, 80 
Cross-grain. Effect on strength, 51 
Crushing resistance of wood, 26 
Cucumber. Identification, 131 

structure, 121 
Cupping, 10, 16, 25, 31 

plywood, 39 
Cushioning material for protecting 

contents, 74 
Cutting of veneer, 37 
Cypress. Rules for grading, 160 

structure, 126 

see also Bald cypress 

D 

Decay, 31 

Defects in lumber. Defined, 8 

effect on strength of box, 48 

effect on strength of crate, 81 

specifications, 99 
Density of wood, 15 

relation to design, 45 

relation to nail-holding power, 
51 

relation to size of nail head, 57 

relation to spacing of nails, 56 
Design. Efficiency shown by tests. 
87 

see Box design ; Crate design 
Detached tops in wirebound boxes, 
107 



202 



INDEX 



Deterioration in stored lumber, 31 
Diagonal nailing, 53 
Diffuse-porous woods, 112, 128 
Direction of grain. How deter- 
mined, 114 
Directions for nailing, 55 

in crates, 82 
Disassembling of contents for ship- 
ment, 72) 

in crates, 86 
Displacement. Importance in ex- 
port shipments, 7?) 
Dote, 9 _ 
Dovetail boxes, 67 
Douglas fir. Identification, 134 

structure, 124 
Douglas spruce. Structure, 124 
Drop-cornerwise test, 92 
Drop-edgwise test, 92 
Drum test, 91 
Dry rot. Prevention, 2>2 
Drying, see Seasoning 



E 



Eastern white pine. Identification, 

133 
Elm. Identification, 127 
structure, 119 

see also Rock elm ; Slippery 
elm ; Soft elm 
Engelmann spruce. Identification, 

134 
Equipment. Box making, 42 
Export containers. Nailing, 55 
strength requirements, 72 
strength requirements of crates, 

85 
woods not to be used, 32 



Fassnacht type of box. Battens, 69 
Fastenings and reinforcements. Cor- 
ner irons, 62 

crate, 82 

hand-holds, 62 

handles, 62 

hinges, 62 

metal handles, 64 

nails, 53 

rope handles, 63 

screws, 59 

staples, 59 

webbing handles, 63 
Fiber-saturation point, 16, 20 
Fiber, Wood, 113 



Fir. Identification, 136 

structure, 126 

see also Alpine fir; Balsam fir; 

Douglas fir ; Noble fir ; Red 

fir. White fir 

"Flotation." Method of packing, 74 

Foundations and skids in lumber 

yard, 35 
4-One boxes, see Wirebound boxes. 
Fragile contents. Protection, 74 
Frame members of crates, 78 

skids, 79 
Fungous growth in lumber, 31 

stain, 110 
Fusiform rays, 114 



Grades of lumber. According to 
size, 10 
association rules, 11 
how determined, 8 
rules for rotary cut, 137 
suitable for boxes and crates, 11 

Green ash. Identification, 127 
structure, 119 

Grouping of woods, 100 

for wirebound boxes, 104 

Gum, see Black gum ; Cotton gum ; 
Red gum 

Gum spots, 10 



H 



Hackberry. Identification, 127 

structure, 118 
Hand-holds, 62 
Handles, 62 
Hard maple. Identification, 130 

structure, 121 
Hardness of wood, 30 
Hardware type of box, 66 
Hardwood. Identification,' 117 

structure, 112 

use in boxes, 126 
Hazards of transportation. Effect 
on box design, 71 

effecf on crate design, 85 

export shipping, 72 
Heartwood. Construction, 109 
Hemlock. Identification, 136 

rules for grading, 151 

structure, 126 

see also Western hemlock 
Hinges, 62 
Holding power of nails, 55 

see also Nail holding power of 
wood 
Floneycombing of lumber, 25, 31 



INDEX 



203 



Identification of woods, 108 

key, 117 

procedure, 115 

wood structure, 109 
Insect attack on lumber, 2>2 

effect on strength of box, 51 
Internal bracing, sec Bracing 
Interstate Commerce Commission, 74 



J 



Jack pine. Structure, 123 
Joints, 43 

butt, 44 

Linderman, 44 

inatched, 44 

serviceability of nailed joints, 
51 

specifications, 101 

strength affected by overdriv- 
ing nails, 58 

width, 43 

wirebound box, 68 



K 



Kiln-drying of wood, 16, 36 

collapse of wood, 23 

objections to kiln-drying, 22 

to avoid stain, 31 
Knots. Defined, 9 

effect on strength, 44, 48 

kinds, 9 



Lag screws. Use in crates, 84 
Larch. Structure, 124 
Linderman joint, 44, 101 
Liner for boxes. Sheet metal, 74 

vermin, 76 

water-proof paper, 74 
Lock-corner style of box, 66 

specifications, 103 
Locks, 62 

Lodgepole pine. Structure, 123 
"Log run," 11 
Lumber. Case hardening, 25, 31 

checking, 25, 31 

collapse of wood cells in kiln- 
drying, 23, 31 

color, 25 

consumption by States, 5 

cross-grain, 51 

cupping, 10, 16, 25 

decay, 31 

defects, 8, 48 



deterioration in storage, 31 

grades, 8 

grading rules, 141 

honeycombing, 25, 31 

kiln-drying, 16, 31 

insect attack, iZ 

moisture content, 17 

sec Moisture content 

piling in yard, 2)2, 35 

plywood, 39 

printing, 25 

resawing, 10 

rot, 31 

rules for grading, 141 

salvage value, 1 

seasoning in storage, 30 

shearing, 132 

shrinking, 16, 22 

sizes, 8 

specifications of National As- 
sociation of Box Manufac- 
turers, 99, 103 

stain prevention, 31 

standard defects, 8 

standard sizes, 8, 10 

storage, 30 

storage deterioration, 31 

swelling, 16, 22 

swelling avoided, 23 

thickness of wood in relation to 
size of nail head, 57 

thickness of wood in relation 
to use of strapping, 61 

twisting, 31 

veneer, ?)7 

warping, 16 

waste in manufacturing, 11 

width, 43 

see also Woods 
Lumber yard. Methods of piling, 33 

drainage, 33 



M 



Machine bolts in crates, 84 
Magnolia. Structure, 121 
M^anufacturing. Cost of operation, 
42 

equipment, 42 

limitation, 42 

poor, 10 

styles of boxes, 42 
Maple, see Hard maple ; Soft maple. 
Matched joint, 44 
Material. Specifications, 99 

in wirebound boxes, 104 
Mechanical properties of wood, 26 
Medullary rays, 113 



204 



INDEX 



Metal binding. Application, 60 

effect on box shrinkage, 47 

effect on box strength, 60 

for wirebound boxes, 105 

in crates, 84 

nails, 60 

purposes, 60 

staples, 59 

time to apply, 48 

types, 60 
Metal handles, 64 
Metal liner for boxes, 74 
Modulus of rupture, 29 
Modulus of elasticity, 30 
Moisture. How contained in wood, 
16 

fiber saturation point, 16 
Moisture content 

affecting freight charges, 30 

effect in crates, 81 

effect on box strength, 47 

how determined, 15 

how effect on boxes is deter- 
mined, 87 

importance, 15 

proper, 17, 47 

specifications, 99 

variation, 16, 22 
Mortise and tenon in wirebound 
boxes, 68 



N 



Nailed boxes, 64 
Nail holding power of wood, 30 
affected by density of wood, 53, 

65 
affected by design of nail, 53 
affected by moisture content, 15, 
47 

affected by size of nail head, 
57 
tests, 53 
Nailing. Effect on box strength, 91 
Nailing in wirebound boxes, 106 
Nailing of crates. Size and spacing 
of nails, 82 
three-way corner, 77 
Nailing and bolting qualities of 

wood, 81 
Nailing of wooden boxes. Clinch- 
ing. 56 
directions, 55 
overdriving, 30, 58, 102 
side, 56 
specifications, 101 



Nailing qualities of wood. Diag- 
onal nailing, 53 

effect on box strength, 51 

end grain and side grain, 64 

factors affecting, 51 

in crates, 81 
Nailless straps, sec Metal binding 
Nails. Barbed, 55 

box, 53 

cement-coated, 55 

clinching, 56 

crate, 82 

effect of design of nails on 
holding power, 53 

effect of size of head, 57 

overdriving, 30, 58 

selection, 30 

size in crates, 82 

spacing, 55, 102 

spacing in crates, 55, 101 

strapping, 60 
Nesting of contents, 72> 
Nets. Use in export shipping, 72 
New England spruce. Rules for 

grading, 145 
New England balsam. Rules for 

grading, 159 
Noble fir. Identification, 136 
Non-porous wood, 114 
North Carolina pine, sec Southern 

yellow pine 
Northern white cedar. Identifica- 
tion, 132 
Norway pine. Identification, 134 

structure, 123 



O 



Oak. Identification, 126 
rules for grading, 158 
structure, 118 

Odor of wood, 26 

in identification, 116 

Ordnance boxes, 43 

Oregon pine. Structure. 124 

Oven-dry weight, 15 

Overdriving of nails, 30, 58, 102 



Packing for fragile contents, 75 

Panel boxes, 70 

Paper liner. Use as waterproofing, 

74 
Parenchyma tissue, 113 
Partitions in boxes, 75 
Physical properties of woods, see 

Woods 



INDEX 



205 



Pilferage. Protection against, 76 
relation to fastenings, 59, 62 
sheathing as crate protection 

against stealing, 81 
strapping as pilferage preven- 
tion for boxes, 60 
Piling lumber in yard. Foundations 
and skids, 35 
placing, 36 
proper methods, iZ 
size and spacing of piles, 36 
stickers, 35 
Pine. Structure, 123 

white, identification, 133 
rules for grading, 141 
see also Eastern white pine ; 
Sugar pine; Western white 
pine 
yellow, identification, 134 
rules for grading, 143 
see also Jack pine ; Lodge- 
pole pine ; Norway pine ; 
Pitch pine : Scrub pine ; 
Yellow pine 
Pitch pine. Structure, 123 
Pitch-pockets, 9, 115 
Pitch streaks. 9, 115 
Pith, 9 

Pith-flecks,^ 113 
Plywood. Use, 39 

in panel boxes, 70 
Poor manufacture of lumber, 10 
Poplar, yellow (tulip). Rules for 
grading, 150 
structure, 121 
Popple. Identification, 129 

structure, 122 
Pores. Construction in hardwood, 
112 
in identification, 116 
Port Orford cedar. Identification, 
133 
structure, 122 
Powder post beetle, 32 
Printing on boxes, 25 

selection of wood, 30 
Protection of fragile contents, 74 
Pumpkin ash. Identification, 127 

structure, 119 
Puncturing. Infrequence in boxes, 
46 
plywood, 39 
resistance of panel boxes, 70 

Q 

Quarter-sawed lumber for special 

boxes, 23 
Quarter-sawing, 113 



R 

Rafting pin holes, 10 
Rays, Fusiform, 114 

medullary, 113 
Red cedar. Structure, 122 
Red cedar. Western, see Western 

red cedar 
Red fir. Identification, 136 
Red gum. Identification, 130 

rules for grading, 147 

structure, 121 
Red oak. Identification, 126 

rules for grading, 158 

structure, 118 
Red spruce. Identification, 134 
Redwood. Identification, 135 

structure, 126 
Reinforcements, 53, 62 

bracing long crates, 79 

corrugated fasteners, 44 

see also Fastenings 
Resawing. Bo.x lumber, 10 

into veneer, 37 
Resin content, 15 
Resin ducts, 114 
Returnable boxes, 43 

corner irons, 62 

handles, 62 
Ring porous woods, 112 
Rings, Annual, 110 
Rock elm. Identification, 127 

structure, 119 
Rods, Binding, 84 
Rope handles, 63 
Rot. 9, 31 

extent permissible, 51 
Rotary-cut lumber. Drying, 36 

method of cutting, 37 

rules for grading, 137 

use in wirebound boxes, 67 
Round-edge lumber, 11 
Rust. Treatment of metal bindings, 
61 



Salvage value of wooden boxes, 1 
Sap gum, see Red gum 
Sapstain, 31 

Sapwood. Structure, 109 
Scabbing in crates, 80 
Schedule of nailing, 101 
Screws. Advantages and disadvan- 
tages, 59 
use of lag screws in crates, 84 
Scrub pine. Structure, 123 
Sealing of boxes, 59 



206 



INDEX 



Seasoning of lumber. In storage, 30 

to avoid stain, 31 

veneer, 38 
Second-hand boxes. Caution in use, 2 
Shake. Effect on strength of box, 

9, 50 
Shearing, 22 

effect of strapping, 60 

resistance, 26 

resistance of crates, 79 
Shearing strength of wood, 26 

affected by size of nail head, 57 
Sheathing in crates, 81 
Sheet metal liner for boxes, 74 
Shiplap joint, 44 
Shock resisting abilitv of wood, 22, 

30 
Shrinkage of wood, 16, 22 

allowance for, 17 

how avoided, 23 

plywood, 39 

vertical cleats, 65 
Side nailing, 56, 102 
Sitka spruce. Identification, 134 

rules for grading, 145 

structure, 124 
Size of box. How determined, 73 

traffic limitations, 7i 
Size of crate. How determined, 86 
Sizes of box lumber, 8 
Skids in lumber yard, 35 
Skids on crates, 79 
Slippery elm. Structure, 119 
Sodium carbonate as stain preven- 
tive, 31 
Soft elm. Rules for grading, 153 
Soft maple. Identification, 130 

rules for grading, 153 

structure, 121 
Softwood. Structure, 114 
Southern yellow pine. Identifica- 
tion, 134 

rules for grading, 143 

structure, 123 
Spacing of nails, 55, 102 

side, 56 
Spacing of staples in wirebound 

boxes, 106, 107 
Special constructions, 74 
Species of box wood. Choice, 2, 14 

see Lumber; Woods 
Specifications. 4-One boxes, 103 

grade of lumber, 11 

lock-corner boxes, 103 

nailed boxes, 99 

purpose. 97 

standardization of packing 
boxes, 98 
Specific gravity of woods, 14 



Splines. Use in trays, 76 
Splits, 9 

effect on box strength, 45 

how avoided in crates, 82 

in plywood, 39 

relation to size of nails, 56 

relation to spacing of nails, 55 

use of corrugated fasteners, 45, 
50 
Springwood, 110 
Spruce. Identification, 134 

rules for grading, 145 

structure, 124 

see also Douglas spruce ; Engel- 
mann spruce ; Sitka spruce ; 
White spruce ; Red spruce 
Staggered nailing in crates, 82 
Stain, 9, 110 

prevention, 31, 36 
Standard sizes of box lumber, 8 
Standardization of design, 42 

of boxes, 99 

styles of nailed boxes, 64 
Staples, 59 

wirebound boxes, 105 
Step-rnitre in wirebound boxes, 68 
Stickers in piled lumber, 35 
Stiffness of wood, 30 

influence on box strength, 45 

plywood, 39 
Storage. Possible deterioration of 
lumber, 30 

proper methods of piling, 22 

seasoning of lumber, 30 
Strapping, see Metal binding. 
Strength of boxes. Affected by 
nailing, 91 

how determined, 87 

relation to contents, 70 
Strength of crates. Affected by 
stiffness of wood, 45 

affected by reinforcements, 84 

affected bj'- style, 77 

factors determining, 85 
Strength properties of wood, 26, 81 

as a beam, 28 

compression, 26 

hardness, 30 

meaning, 26 

nail holding power, 30 

of balanced boxes, 43 

shearing, 26 

shock resisting ability, 22, 30 

stiffness, 30 

tensile, 26 
Structure of wood species, 109 

conifers, 114 

hardwoods, 112 



INDEX 



207 



Styles of boxes, 42 

characteristics, 64 

dovetail boxes, 57 

hardware type, 66 

lock-corner boxes, 66 

nailed boxes, 64 

panel boxes, 70 

standard styles, 64 

wirebound boxes, 67 
Styles of crates, 77 
Sugar maple, sec Hard maple 
Sugar berry, sec Hackberry 
Sugar pine. Identification, 133 

rules for grading, 161 

structure, 123 
Summerwood, 110 
Surfacing of boxes, 101 
Swelling of wood, 16, 22 

how avoided, 23 
Sycamore. Identification, 129 

structure, 120 



T 



Tamarack. Structure, 124 

Taste of wood, 26 

in identification, 116 

Tensile strength of wood, 26 

Tensile strength of strapping. Af- 
fected by annealing, 60 

Testing of boxes and creates, 87 
compression-on-an-edge test, 92 
compression-cornerwise test, 96 
compression-on-faces test, 96 
drop-cornerwise test, 92 
drop-edgewise test, 92 
drum test, 91 
information obtained, 87 
sup4)lementary tests, 96 

Thickness of box parts, 100 

relation to size of nailhead, 57 
relation to strapping, 61 
relation to wood groups, 103 
variation allowable, 101 
in wirebound boxes, 105 

Thickness of crate parts, 81 

Thieving, sec Pilferage 

Three-way-corner con.struction. Box 
66 
crate, 77 

Tie rods, sec Binding rods 

Traffic limitations on box design, 74 
85 

Tracheids, 114 

Transportation hazards, sec Haz- 
ards. 

Trays. Use in boxes, 76 

Tulip, sec Poplar, yellow 



Tupelo. Rules for grading, 157 

structure, 122 
Twisting, 10, 31 

of plywood, Z7 
Tyloses, 112 
Types of crate corner, 77 

U 

Unannealed strapping, 60 

V 

Veneer. Availaliility, 41 

definition, i7 

drying, 36 

method of cutting, i7 

plywood, 39 

woods used in box veneer, 38 
Vermin. Protection, 76 
Virginia pine, see Southern yellow 
pine 

W 

Wane, 9 

Warped lumber. Use in boxes, 46 

use in crates, 81 
Warping, 10, 16 

Washers. Use on crate bolts, 84 
Waste in lumber use, 11 
Waterproof paper. Use, 74 
Waterproof crate covers, 81 
Weaving. Resistance, 43 

in crates, 78 
Webbing handles, 63 
Wedgelock ends in wirebound boxes, 

1C6 
Weight of boxes. How determined, 
7i 
reduced by strapping, 60 
Weight of wood. Factors influenc- 
ing, 15 
how determined, 15 
how expressed, 14 
importance, 14 
Western hemlock. Identification, 136 
Western red cedar. Identification, 

132 
Western white pine. Identification, 
133 
rules for grading, 141 
see also Yellow pine. Western 
Western • yellow pine, see Yellow 

pine 
White ash. Identification, 127 

structure, 119 
White cedar, see Northern white ce- 
dar 
White elm. Identification, 127 
structure, 119 



208 



INDEX 



White fir. Identification, 136 
White oak. Identification. 126 

rules for grading, 158 

structure, 118 
White pine. Structure, 123 

Eastern identification, 133 
rules for grading, 141 

Western identification, 133 

sec also Yellow pine. Western 
White spruce. Identification, 134 
Width of pieces, 101 

joints, 43 

stock, 43 
Willow. Structure, 120 
Wire bands, see Metal binding 
Wirebound box, 67 

assembling. 105 

closing, 107 

construction, 104 

grouping of woods, 104 

material, 104 

specifications, 103 

with detached tops, 107 

with wedgelock ends, 105 
Wood fibers, 113 
Woods used in boxes and crates. 

Amount of each species, 2 

availability, 1 

choice, 2 

cost, 1 

choice in relation to design, 45 

compression strength, 26 

density, 15 

description, 126 

desirable qualities, 2 

distribution, 5 

fiber saturation point, 16 

fungous growth, 31 

geographical distribution by 
States, 126 

grouping, 100, 104 

hardness, 30 



identification, 115 
kinds, 3 

mechanical properties, 26 
moisture content, 15 

see also Moisture content 
nail holding power, 15, 30 
nailing qualities, 51 
odor, 26 

physical properties, 14 
properties which influence use 

in box construction, 14 
resin content, 15 
salvage value, 1 
shearing strength, 26 
shock resisting ability, 22, 30 
sources, 5 
species, 2 

specific gravity, 14 
stiffness, 30 
strength properties, 26 
structure, 108 
taste, 26 

tensile strength, 26 
veneer, 38 
weight, 14 
see also Lumber 
Worm holes, 10 

effect on bo.x strength, 51 



Yellow buckeye. Identification, 132 
Yellow pine. Southern. Identifica- 
tion, 134 

rules for grading, 143 
structure, 123 
Western. Identification. 134 
rules for grading, 148 
structure, 123 
Yellow poplar. Identification, 131 
rules for grading, 150 
structure, 121 



H 137 80 







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